Test method for transmission performance of large-torque reduction gearbox of unmanned aerial vehicle

Abstract

The application discloses a kind of unmanned aerial vehicle large torque reduction gearbox transmission performance test methods, it is related to unmanned aerial vehicle reduction gearbox transmission performance test technical field, the method is according to the structure parameter of to-be-measured reduction gearbox Specialized adaptation tooling is customized, reduction gearbox is clamped and fixed in test bench, completes driving end and load end coaxial precision calibration, and simultaneously realizes the installation and signal calibration of various sensors;Based on the multi-dimensional test working condition matrix of unmanned aerial vehicle full flight profile is constructed, the no-load reference performance test and transmission loss calibration of test system are carried out;According to working condition matrix, full load performance test, dynamic response test and high-low temperature environmental adaptability test are carried out in turn, based on full working condition data, the quantitative evaluation of reduction gearbox comprehensive transmission performance is carried out, fatigue durability test is carried out simultaneously, and finally, standardized test report is formed.The application can effectively reduce system error, improve test data precision, fully characterize the transmission characteristics of reduction gearbox, and promote the standardization and normalization of unmanned aerial vehicle reduction gearbox test process.

Description

Technical Field

[0001] This invention relates to the field of testing technology for the transmission performance of UAV gearboxes, and more particularly to a method for testing the transmission performance of high-torque UAV gearboxes. Background Technology

[0002] With the rapid development of the drone industry, large-payload, long-endurance industrial-grade drones have achieved large-scale application in various fields such as logistics transportation, inspection operations, and emergency rescue. These drones place more stringent requirements on the high-torque gearbox, a core component of the power transmission system, in terms of transmission efficiency, load-bearing capacity, transmission accuracy, environmental adaptability, and reliability. As the core transmission component of the drone's power system, the gearbox's comprehensive transmission performance directly determines the drone's power output stability, flight control accuracy, and overall flight safety. Therefore, comprehensive, accurate, and scenario-specific transmission performance testing throughout the entire process of gearbox research and development, manufacturing, and product finalization is a crucial link in ensuring product quality and flight safety.

[0003] Current testing methods for gearbox transmission performance are mostly gearbox designs with fixed speeds and fixed loads in general industrial applications. The test conditions are often single, stable rated load conditions, failing to consider the complex and varied working scenarios of UAVs during flight, such as hovering, constant speed cruise, high-maneuver overload, gust resistance, and vertical takeoff and landing. This lack of a test condition matrix that matches actual flight loads leads to significant discrepancies between laboratory test data and the actual performance of the gearbox during flight, failing to fully reflect its performance in real-world operating environments. Furthermore, existing testing methods often lack systematic pre-calibration and dynamic compensation for transmission losses on the test bench itself, and have insufficient control over the accuracy of the test system's installation coaxiality and bench leveling. This easily introduces additional loads and systematic errors during testing, reducing the accuracy of test data and the repeatability of results from different batches.

[0004] Furthermore, existing testing systems primarily focus on basic transmission performance testing of gearboxes under ambient temperature conditions, lacking sufficient coverage for performance changes under extreme operating environments such as high-altitude low-temperature and near-ground high-temperature conditions for UAVs. They also lack a fatigue durability testing system that matches the design lifespan of UAVs, making it impossible to effectively predict the performance degradation trend and potential failure risks of gearboxes throughout their entire lifecycle. Simultaneously, the industry lacks a unified quantitative evaluation system for the transmission performance testing of high-torque gearboxes for UAVs. Significant differences exist in testing procedures, evaluation indicators, and operating condition settings among different testing entities, making standardized horizontal comparisons of the performance of different batches and models of gearboxes impossible. This also hinders the formation of unified industry testing standards, impeding technological iteration and end-to-end quality control of UAV power transmission systems. Summary of the Invention

[0005] The present invention proposes a method for testing the transmission performance of a high-torque reduction gearbox for unmanned aerial vehicles (UAVs) to solve the problems mentioned in the prior art.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a method for testing the transmission performance of a high-torque reduction gearbox for unmanned aerial vehicles, comprising the following steps: Customized tooling was designed based on the installation interface and dimensions of the high-torque reduction gearbox of the UAV under test. The reduction gearbox was fixed on a rigid test bench. The coaxial connection of the drive servo motor, torque and speed sensor and magnetic powder load device was completed. The coaxiality of the drive end, reduction gearbox and load end was calibrated by laser alignment instrument. The installation and signal calibration of vibration, temperature and noise sensors were completed simultaneously. The benchmark parameter file of the test system was established. Based on the actual load of the UAV in all flight conditions, a multi-dimensional test condition matrix is ​​constructed, covering the speed and torque load conditions under different flight modes. The test duration, load loading rate and speed change gradient of each condition are set, and the test data acquisition frequency and key acquisition nodes are determined. The drive motor is controlled to perform a step-by-step speed increase and decrease cycle according to the preset no-load speed gradient. No-load transmission torque, input-output speed difference, vibration acceleration, operating noise and shell temperature parameters are collected. The no-load transmission efficiency, return clearance and no-load power loss benchmark values ​​are calculated to complete the pre-calibration and elimination of the transmission loss of the test system itself. Simulated loads are applied step by step according to the test condition matrix. Input and output torque, real-time speed, vibration spectrum, shell temperature distribution, and transmission noise parameters of the gearbox are collected under the rated load stable condition. Dynamic response characteristic data of load step and speed change are collected under dynamic load condition. The gearbox under test was placed in a high and low temperature environment chamber to conduct high and low temperature environment adaptability test, simulating the actual working environment of UAV with high altitude low temperature and near ground high temperature. The rated load performance test was repeatedly performed under the set high and low temperature cycle conditions, and the data on the transmission efficiency change and the influence of thermal deformation on the transmission accuracy of the gearbox under different ambient temperatures were collected. Based on the test data collected under all operating conditions, the comprehensive transmission performance of the gearbox is quantitatively evaluated. The transmission efficiency, load stability, transmission accuracy, vibration and noise characteristics, and environmental adaptability under all operating conditions are calculated. Fatigue durability cycle tests of a set duration are performed, and a standardized transmission performance test report is finally output.

[0007] Furthermore, it also includes precise calibration and dynamic compensation steps for transmission losses in the test system. Before the no-load benchmark performance test, the no-load loss calibration is completed across the entire speed range of the test bench without a gearbox, and the comprehensive loss calculation formula for the test bench system is introduced: ; in To test the overall transmission loss power of the test bench system at the corresponding speed, For the test bench Level test speed, This represents the drag loss coefficient at the corresponding rotational speed. This represents the bearing friction loss coefficient at the corresponding rotational speed. This represents the fixed loss coefficient of the coupling at the corresponding rotational speed. This represents the total number of levels of the test rotational speed gradient.

[0008] Furthermore, it also includes a step to predict the degradation trend of gearbox transmission performance throughout its entire life cycle. After completing basic performance testing and fatigue durability testing, a gearbox transmission performance degradation prediction model is constructed based on performance decay data from different cycle periods to predict the performance decay pattern and service life threshold of the gearbox during the actual flight of the UAV.

[0009] Furthermore, it also includes multi-dimensional safety interlock protection steps throughout the entire testing process. During the test, the power of the drive motor, the vibration amplitude of the gearbox, the housing temperature, and the load parameters of the load device are monitored in real time. When any parameter is detected to exceed the preset safety threshold, the protection process of gradually unloading the load and slowing down and stopping the drive motor is automatically triggered, and the full parameter test data at the moment of the abnormality is locked simultaneously.

[0010] Furthermore, in the coaxiality calibration step, the calibration accuracy of the laser alignment instrument is controlled within 0.02mm, the radial runout deviation of the drive end, reduction gearbox, and load end is controlled within 0.05mm, and the end face runout deviation is controlled within 0.03mm. After calibration, the rigid connection of each component is completed through a high-strength coupling, and the levelness of the test bench is calibrated at the same time, with the levelness deviation of the bench plane controlled within 0.02mm / m.

[0011] Furthermore, in the step of constructing a multi-dimensional test condition matrix, the test duration of the rated load condition is not less than 30 minutes, the number of load step changes in the variable load dynamic condition is not less than 20, the gradient of the speed change covers the entire range from 0 to the rated speed during the flight of the UAV, and at the same time, at least 3 sets of extreme overload conditions are set, and the extreme load torque is not less than 1.5 times the rated torque of the gearbox.

[0012] Furthermore, in the step of quantitatively evaluating the comprehensive transmission performance of the gearbox, a multi-dimensional weighted comprehensive performance scoring formula is introduced: ; in The overall score represents the comprehensive transmission performance of the gearbox under test. Standardize the scoring for the transmission efficiency dimension. Standardized scoring for transmission accuracy dimension. Standardize the scoring for the vibration and noise dimension. Standardize the scoring for the environmental adaptability dimension. Standardize the scoring for the reliability and lifespan dimension. , , , , These are the weight coefficients for the corresponding dimensions, and the sum of all weight coefficients is 1.

[0013] Furthermore, during the acquisition of vibration acceleration parameters, a triaxial accelerometer is used for vibration detection, which is respectively installed at the input shaft end, output shaft end, and middle of the gearbox housing; during the acquisition of operating noise parameters, a microphone is used for noise detection, which is placed 1 meter away from the gearbox housing; spectrum analysis is performed on the test data to identify fault characteristics such as abnormal gear meshing, bearing wear, and shaft misalignment.

[0014] Furthermore, in the fatigue durability cycle test, the cycle test conditions adopt the load spectrum of a typical UAV flight mission. A single cycle includes the entire process of no-load start-up, rated load operation, overload impact, and deceleration shutdown, with the duration consistent with the typical flight duration of a single UAV flight. The total number of cycles is not less than the total number of flights within its design service life. A benchmark performance test is performed at fixed intervals of cycles, and the transmission performance decay law is recorded. After the test, the gears, bearings, and shafts are disassembled and inspected for wear and fatigue damage.

[0015] Furthermore, in the high and low temperature environment adaptability test, the low temperature test environment temperature is set to -40℃, the high temperature test environment temperature is set to 60℃, the temperature change rate during the high and low temperature cycle is controlled at 2℃ per minute, the heat preservation time at each temperature point is not less than 2 hours, and the performance test is performed after the gearbox as a whole reaches the set temperature; the viscosity change and lubrication status of the internal lubricating oil are monitored simultaneously to evaluate the comprehensive impact of extreme temperatures on the lubrication system and transmission performance.

[0016] Compared with existing technologies, the beneficial effects of this invention are: This method constructs a multi-dimensional test condition matrix covering all flight scenarios, targeting the actual working characteristics of high-torque gearboxes in UAVs. It can comprehensively simulate various working states of the gearbox during actual UAV flight, making the test process highly consistent with the real use scenario of the gearbox. The test results can truly reflect the actual working performance of the gearbox, providing reliable measured data support for the research and development, finalization, and performance optimization of the gearbox.

[0017] This method, through high-precision calibration of the system coaxiality and bench levelness before testing, combined with pre-calibration and dynamic compensation of the test bench's own transmission losses, can effectively eliminate the interference of system errors such as installation deviations and inherent bench losses on test results, improve the accuracy and stability of test data, and ensure the repeatability of test results from different batches.

[0018] This method constructs a comprehensive testing process system, covering multiple testing stages such as no-load benchmark performance testing, rated load stability testing, dynamic variable load response characteristic testing, high and low temperature environment adaptability testing, and fatigue durability testing. It can comprehensively and systematically evaluate the overall transmission performance of the gearbox, accurately identify weak links and potential failure risks in the gearbox transmission process, and provide clear technical directions for gearbox structure optimization, material selection, and lubrication scheme improvement.

[0019] This method establishes a multi-dimensional weighted comprehensive transmission performance quantitative evaluation system, which can transform scattered performance test data into unified standardized evaluation results. It enables standardized horizontal comparison of the transmission performance of high-torque gearboxes of different batches and models of UAVs, which helps to promote the formation of unified test and evaluation standards in the industry and improve the standardization level in the field of UAV gearbox testing.

[0020] This method establishes a multi-dimensional safety interlock protection mechanism for the entire testing process, which can monitor and respond to various abnormal conditions in real time during the testing process, ensuring the safety of equipment and personnel during the testing process. At the same time, it can completely lock the full parameter test data at the moment of the abnormality, providing complete data support for subsequent fault analysis and performance improvement. Attached Figure Description

[0021] Figure 1 This is a schematic block diagram of the UAV high-torque reduction gearbox transmission performance testing method proposed in this invention; Figure 2 This is a multi-dimensional test condition matrix and execution state transformation diagram; Figure 3 For accurate calibration and dynamic compensation closed-loop diagram of test bench wear; Figure 4 Architecture diagram for comprehensive performance quantitative evaluation and fatigue life prediction; Figure 5 This is a multi-dimensional safety interlock protection control diagram for the entire testing process. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0024] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly; for example, they may refer to a fixed connection, a detachable connection, or an integral connection; they may refer to a mechanical connection or an electrical connection; they may refer to a direct connection or an indirect connection through an intermediate medium; and they may refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances. The invention will now be described in further detail with reference to the accompanying drawings.

[0025] Reference Figures 1 to 5 A method for testing the transmission performance of a high-torque reduction gearbox for unmanned aerial vehicles (UAVs), comprising the following steps: Customized tooling was designed based on the installation interface and dimensions of the high-torque reduction gearbox of the UAV under test. The reduction gearbox was fixed on a rigid test bench. The coaxial connection of the drive servo motor, torque and speed sensor and magnetic powder load device was completed. The coaxiality of the drive end, reduction gearbox and load end was calibrated by laser alignment instrument. The installation and signal calibration of vibration sensor, temperature sensor and noise sensor were completed simultaneously. The benchmark parameter file of the test system was established. Based on the actual working load of the UAV in all flight scenarios, a multi-dimensional test condition matrix is ​​constructed, covering the speed and torque load conditions corresponding to the entire scenario of hovering, constant speed cruise, high maneuver overload, wind resistance, and vertical take-off and landing. The test duration, load loading rate, and speed change gradient of each condition are set, and the acquisition frequency and key acquisition nodes of the test data throughout the process are determined simultaneously. The drive motor is controlled to complete the step-by-step acceleration and deceleration cycle according to the preset no-load speed gradient. The no-load transmission torque, input-output speed difference, vibration acceleration, operating noise, and shell temperature parameters of the gearbox are collected. The reference values ​​of the gearbox's no-load transmission efficiency, return clearance, and no-load power loss are calculated to complete the pre-calibration and elimination of the transmission loss of the test system itself. Simulated loads are applied step by step according to the test condition matrix. Under the rated load stable condition, the input and output torque, real-time speed, vibration spectrum, shell temperature distribution, and transmission noise parameters of the gearbox are collected. Under the dynamic load condition, the dynamic response characteristics data of the load step and speed change process are collected, and the impact abnormal signal in the transmission process is recorded simultaneously. The gearbox under test was placed in a high and low temperature environment chamber to simulate the actual working environment of the UAV at high altitude low temperature and near ground high temperature. The rated load performance test was repeatedly performed under the set high and low temperature cycle conditions, and the data on the transmission efficiency change and the influence of thermal deformation on the transmission accuracy of the gearbox under different ambient temperatures were collected. Based on the test data collected under all operating conditions, a quantitative evaluation of the overall transmission performance of the gearbox is completed. The transmission efficiency, load holding capacity, transmission accuracy stability, vibration and noise level, and environmental adaptability indicators under all operating conditions are calculated. A fatigue durability cycle test of a set duration is performed to complete the fatigue life and reliability verification of the gearbox, and finally a standardized transmission performance test report is output.

[0026] This invention also includes precise calibration and dynamic compensation steps for transmission losses in the test system. Before the no-load benchmark performance test, the no-load loss calibration is completed across the entire speed range of the test bench without a gearbox, and the comprehensive loss calculation formula for the test bench system is introduced: ; in To test the overall transmission loss power of the test bench system at the corresponding speed, For the test bench Level test speed, This represents the drag loss coefficient at the corresponding rotational speed. This represents the bearing friction loss coefficient at the corresponding rotational speed. This represents the fixed loss coefficient of the coupling at the corresponding rotational speed. To test the total number of speed gradients, multi-parameter coupling calculations can accurately quantify the inherent losses of the test bench system at different speeds. In subsequent gearbox performance testing, the measured power data can be dynamically compensated to eliminate the interference of the test bench system's own losses on the gearbox transmission performance test results, thereby improving the accuracy and authenticity of the test data.

[0027] This invention also includes a step for predicting the degradation trend of gearbox transmission performance throughout its entire life cycle. After completing basic performance testing and fatigue durability testing, a gearbox transmission performance degradation prediction model is constructed based on performance decay data from different cycle periods. This model predicts the performance decay pattern and service life threshold of the gearbox during actual UAV flight, providing quantitative data support for the maintenance and replacement cycle of the gearbox and flight safety management.

[0028] This invention also includes a multi-dimensional safety interlock protection step throughout the entire testing process. During the test, the power of the drive motor, the vibration amplitude of the gearbox, the housing temperature, and the load parameters of the load device are monitored in real time. When any parameter is detected to exceed the preset safety threshold, the protection process of gradually unloading the load and slowing down and stopping the drive motor is automatically triggered. The full parameter test data at the moment of the abnormality is locked simultaneously to avoid equipment damage and destructive damage to the gearbox under test during the test.

[0029] In this invention, during the coaxiality calibration step, the calibration accuracy of the laser alignment instrument is controlled within 0.02 mm, the radial runout deviation of the drive end, reduction gearbox, and load end is controlled within 0.05 mm, and the end face runout deviation is controlled within 0.03 mm. After calibration, a high-strength coupling is used to achieve rigid connection of each component. At the same time, the test bench is leveled, and the levelness deviation of the bench plane is controlled within 0.02 mm per meter, eliminating the interference of additional load caused by installation deviation on the test results during the test.

[0030] In this invention, during the construction of the multi-dimensional test condition matrix, the test duration of the rated load condition is no less than 30 minutes, the number of load step changes in the variable load dynamic condition is no less than 20, the gradient of the speed change covers the entire range from 0 to the rated speed during the flight of the UAV, and at the same time, at least 3 sets of extreme overload conditions are set, with the extreme load torque being no less than 1.5 times the rated torque of the gearbox, to verify the transmission stability and overload tolerance of the gearbox under extreme conditions.

[0031] In this invention, the quantitative evaluation step of the gearbox's comprehensive transmission performance introduces a multi-dimensional weighted comprehensive performance scoring formula: ; in The overall score represents the comprehensive transmission performance of the gearbox under test. Standardize the scoring for the transmission efficiency dimension. Standardized scoring for transmission accuracy dimension. Standardize the scoring for the vibration and noise dimension. Standardize the scoring for the environmental adaptability dimension. Standardize the scoring for the reliability and lifespan dimension. , , , , These are the weight coefficients for the corresponding dimensions, and the sum of all weight coefficients is 1. The weight coefficients can be dynamically adjusted according to different application scenarios of the drone. Through the weighted coupling calculation of multi-dimensional indicators, the scattered multi-dimensional test data can be transformed into a unified quantitative scoring result, realizing an intuitive comparison and graded evaluation of the transmission performance of different batches and models of gearboxes.

[0032] In this invention, during the acquisition of vibration and noise parameters, a triaxial accelerometer is used as the vibration sensor, which is installed at the input shaft end, output shaft end, and middle of the housing of the gearbox. The acquisition frequency of the vibration signal is not less than 20kHz, covering more than 10 times the gear meshing frequency of the gearbox. The noise test uses a microphone, which is placed 1 meter away from the gearbox housing. The background noise of the test environment is not higher than 35dB. At the same time, the test data is subjected to spectrum analysis to identify the fault characteristics of abnormal gear meshing, bearing wear, and shaft misalignment in the gearbox transmission process.

[0033] In this invention, the fatigue durability cycle test step uses the load spectrum of a typical UAV flight mission as the test condition. Each cycle covers the entire process from no-load start-up, rated load operation, overload impact to deceleration and shutdown. The duration of each cycle is consistent with the duration of a typical single flight of the UAV. The total number of cycle tests is not less than the total number of flights within the UAV's design service life. During the test, a gearbox benchmark performance test is performed once every fixed number of cycles, and the attenuation and change law of transmission performance are recorded. After the test, the gearbox is disassembled to check the wear and fatigue damage of gears, bearings, and shafts.

[0034] In this invention, during the high and low temperature environment adaptability test, the low temperature test environment temperature is set to -40℃, the high temperature test environment temperature is set to 60℃, the temperature change rate during the high and low temperature cycle is controlled at 2℃ per minute, and the heat preservation time at each temperature point is not less than 2 hours. This ensures that the overall temperature of the gearbox reaches the set value before the performance test is performed. At the same time, during the high and low temperature test, the viscosity change and lubrication status of the lubricating oil inside the gearbox are monitored to evaluate the comprehensive impact of extreme temperature environment on the gearbox lubrication system and transmission performance.

[0035] The following two examples further illustrate specific embodiments of the present invention: Example 1: Implementation of Transmission Performance Test for High-Torque Gearbox of High-Patient Logistics UAV This embodiment applies to a high-torque planetary gear reducer for a 50kg-class logistics transport drone. The reducer has a rated input speed of 3000 r / min, a rated output torque of 800 N·m, and a transmission ratio of 16:1. It is compatible with the drone's six-rotor power system. The core testing objective is to comprehensively verify the reducer's transmission performance, overload tolerance, environmental adaptability, and fatigue durability under all flight scenarios in logistics transport, providing standardized testing basis for product finalization and mass production. This embodiment fully covers all technical solutions of the method, and all steps and the overall method design are completely consistent, with no technical content exceeding the design scope.

[0036] This embodiment implements a method for testing the transmission performance of a high-torque reduction gearbox in a UAV. First, the customization of the adapter fixture and the installation and calibration of the test bench are completed. A steel adapter fixture is customized based on the reduction gearbox's flange mounting interface, center height, and overall dimensions. The mounting holes of the fixture perfectly match the reduction gearbox. The reduction gearbox is then fixed to a cast iron rigid test bench using high-strength bolts. Coaxial connection of the drive servo motor, torque and speed sensor, and magnetic powder load device is completed. Coaxiality calibration of the drive end, reduction gearbox, and load end is performed using a laser alignment instrument, with calibration accuracy controlled within 0.02mm, radial runout deviation within 0.05mm, and end face runout deviation within 0.03mm. The installation and signal calibration of the triaxial accelerometer vibration sensor, patch-type temperature sensor, and high-precision microphone were completed simultaneously. The vibration sensor was installed at the input shaft end, output shaft end, and middle of the gearbox housing, respectively. The temperature sensor was attached to the gearbox bearing housing and gearbox housing surface. The microphone was positioned horizontally 1 meter away from the gearbox housing. The background noise of the test environment was controlled within 35dB. Finally, the baseline parameter file of the test system was established. At the same time, the levelness of the test bench was calibrated, and the levelness deviation of the bench plane was controlled within 0.02mm per meter. The rigid connection of each component was completed through a diaphragm-type high-strength coupling.

[0037] Subsequently, based on the actual working loads of logistics drones across all flight scenarios, a multi-dimensional test condition matrix was constructed. This matrix covers no-load, 30% rated load, 50% rated load, 100% rated load, and 150% extreme overload conditions, corresponding to the speed and torque loads across all scenarios including vertical takeoff and landing, hovering loading, constant speed cruise, high-maneuver turning, and sudden wind resistance. The test duration for the stable rated load condition was set at 40 minutes, the number of load step changes for the dynamic load condition was set at 25, and the speed change gradient covered the entire range from 0 to 3000 r / min. Three extreme overload conditions at 150% rated torque were set, each with a test duration of 5 minutes. The data acquisition frequency for the entire test process was simultaneously determined to be 50 kHz, with key acquisition nodes corresponding to various time points including load switching, speed change, and temperature stabilization.

[0038] Before formal testing, no-load benchmark performance testing and system loss calibration were completed. Prior to load testing, no-load loss calibration was performed across the entire speed range on the test bench without a gearbox. Inherent transmission loss data of the test bench system at different speeds was collected to establish a test bench loss benchmark database. Subsequently, the gearbox under test was installed, and the drive motor was controlled to complete a series of gradual acceleration and deceleration cycles according to a preset no-load speed gradient, from 0 to 3000 r / min. Each speed level was maintained for 5 minutes, and the gearbox's no-load transmission torque, input-output speed difference, vibration acceleration, operating noise, and housing temperature parameters were collected. Benchmark values ​​for the gearbox's no-load transmission efficiency, return clearance, and no-load power loss were calculated, completing the pre-calibration of the test system's own transmission loss and setting the dynamic compensation scheme for subsequent test data. Throughout the testing process, a multi-dimensional safety interlock protection mechanism was activated, monitoring the drive motor power, gearbox vibration amplitude, housing temperature, and load parameters in real time. If any parameter exceeded a preset safety threshold, the protection process of gradually unloading the load and stopping the drive motor was automatically triggered, simultaneously locking all parameter test data at the moment of the anomaly.

[0039] After calibration, simulated loads were applied step-by-step according to the test condition matrix to conduct full-condition load performance tests. First, stable operation tests under low load conditions were completed, then the load was gradually increased to the rated load condition. The system was then continuously operated under the rated load stable condition for 40 minutes, continuously collecting the gearbox's input and output torque, real-time speed, vibration spectrum, housing temperature distribution, and transmission noise parameters. Subsequently, dynamic variable load condition tests were performed, acquiring dynamic response characteristic data during load jumps and speed abrupt changes. Simultaneously, abnormal impact signals during the transmission process were recorded, and spectral analysis of the vibration signals was performed to identify fault characteristics such as abnormal gear meshing, bearing wear, and shaft misalignment during the gearbox transmission process.

[0040] The gearbox under test, along with its adapter, was then placed in a high-low temperature environment chamber for environmental adaptability testing. The test simulated the actual working environment of a logistics drone, ranging from -40°C at high altitude to 60°C near ground. The temperature change rate during the high-low temperature cycle was controlled at 2°C per minute, and the holding time at each temperature point was 3 hours. After ensuring the overall temperature of the gearbox reached the set value, the rated load performance test was repeated. Data on the changes in transmission efficiency and the impact of thermal deformation on transmission accuracy under different ambient temperatures were collected. Simultaneously, the viscosity change and lubrication status of the lubricating oil inside the gearbox were monitored.

[0041] At the end of the testing phase, based on the test data collected under all operating conditions, a quantitative evaluation of the gearbox's comprehensive transmission performance was completed. Transmission efficiency, load holding capacity, transmission accuracy stability, vibration and noise levels, and environmental adaptability indicators were calculated under all operating conditions. A comprehensive performance score was obtained through multi-dimensional weighted calculation. A 200-hour fatigue durability cycle test was performed. The test conditions adopted the typical flight mission load spectrum of a logistics drone. The duration of a single cycle was consistent with the duration of a single delivery flight of the drone, and the total number of cycles was not less than the total number of flights within the drone's design lifespan. During the test, a benchmark performance test of the gearbox was performed every 20 hours, recording the attenuation and change patterns of transmission performance, and constructing a predictive model for the full life-cycle degradation trend of the gearbox's transmission performance. After the test, the gearbox was disassembled, and the wear and fatigue damage of the gears, bearings, and shafts were inspected. Finally, a standardized transmission performance test report was output.

[0042] Table 1: Performance Comparison of Logistics UAV Gearboxes Using This Method and Traditional Testing Methods

[0043] Table 1 visually demonstrates the comprehensive advantages of this method in the testing scenario of high-load logistics drone gearboxes. Traditional testing methods often employ a single rated load condition, resulting in low matching with actual drone flight scenarios. They also lack calibration compensation for bench system errors, leading to large test data deviations. Furthermore, they can only perform basic performance tests and cannot identify potential faults or predict performance degradation trends. This method constructs a full-flight scenario test condition matrix, improves test accuracy through system error calibration, and comprehensively covers all performance tests of the gearbox. It can accurately identify transmission faults and predict performance degradation patterns, fully adapting to the testing needs of logistics drone gearboxes.

[0044] Example 2: Implementation of Transmission Performance Test of High Torque Gearbox for Long-Endurance Industrial Inspection UAV This embodiment applies to a high-torque helical planetary gearbox for long-endurance industrial inspection drones. The gearbox has a rated input speed of 4500 r / min, a rated output torque of 300 N·m, and a transmission ratio of 12:1. It is compatible with the quadcopter power system of the drone. The core testing objective is to verify the gearbox's transmission stability, adaptability to high and low temperature environments, vibration and noise levels, and overall life-cycle reliability under long-endurance continuous flight conditions. This provides performance verification data for routine operations of inspection drones in high-altitude, cold, and high-temperature environments. This embodiment completely covers all technical solutions of the method, and all steps correspond completely to the overall design of the method, with no technical content exceeding the design scope.

[0045] This embodiment implements a method for testing the transmission performance of a high-torque reduction gearbox in a UAV. First, the customization of the adapter tooling and the installation and calibration of the test bench are completed. An aluminum alloy adapter tooling is customized based on the reduction gearbox's lightweight mounting interface, dimensions, and mounting posture. The mounting holes of the tooling perfectly match the reduction gearbox. The reduction gearbox is then fixed to a cast iron rigid test bench using high-strength bolts. Coaxial connection of the drive servo motor, torque and speed sensor, and magnetic powder load device is completed. Coaxiality calibration of the drive end, reduction gearbox, and load end is performed using a laser alignment instrument, with calibration accuracy controlled within 0.02mm, radial runout deviation within 0.05mm, and end face runout deviation within 0.03mm. The installation and signal calibration of the triaxial accelerometer vibration sensor, patch-type temperature sensor, and high-precision microphone were completed simultaneously. The vibration sensor was installed at the input shaft end, output shaft end, and middle of the gearbox housing, respectively. The temperature sensor was attached to the gearbox bearing housing and gearbox housing surface. The microphone was positioned horizontally 1 meter away from the gearbox housing. The background noise of the test environment was controlled within 35dB. Finally, the baseline parameter file of the test system was established. At the same time, the levelness of the test bench was calibrated, and the levelness deviation of the bench plane was controlled within 0.02mm per meter. The rigid connection of each component was completed through a diaphragm-type high-strength coupling.

[0046] Subsequently, based on the actual working load of the inspection drone across all flight scenarios, a multi-dimensional test condition matrix was constructed. This matrix covers no-load, 40% rated load cruise, 80% rated load wind-resistant, 100% rated load, and 150% extreme overload conditions, corresponding to the speed and torque loads across all scenarios including vertical takeoff and landing, hovering inspection, constant speed cruise, sudden wind resistance, and high-maneuver obstacle avoidance. The test duration for the rated load stable condition was set at 60 minutes, the number of load step changes for the variable load dynamic condition was set at 20, the speed change gradient covered the entire range from 0 to 4500 r / min, and three sets of 150% rated torque extreme overload conditions were set, each with a test duration of 3 minutes. The data acquisition frequency for the entire test process was simultaneously determined to be 50 kHz, with key acquisition nodes corresponding to various time points such as load switching, speed change, and temperature stabilization.

[0047] Before formal testing, no-load benchmark performance testing and system loss calibration were completed. Prior to load testing, no-load loss calibration was performed across the entire speed range on the test bench without a gearbox. Inherent transmission loss data of the test bench system at different speeds was collected to establish a test bench loss benchmark database. Subsequently, the gearbox under test was installed, and the drive motor was controlled to complete a gradual acceleration and deceleration cycle according to a preset no-load speed gradient, from 0 to 4500 r / min. Each speed level was maintained for 3 minutes, and the gearbox's no-load transmission torque, input-output speed difference, vibration acceleration, operating noise, and housing temperature parameters were collected. The gearbox's no-load transmission efficiency, return clearance, and no-load power loss benchmark values ​​were calculated, completing the pre-calibration of the test system's own transmission loss and setting the dynamic compensation scheme for subsequent test data. Throughout the testing process, a multi-dimensional safety interlock protection mechanism was activated, monitoring the drive motor power, gearbox vibration amplitude, housing temperature, and load parameters in real time. If any parameter exceeded a preset safety threshold, the protection process of gradually unloading the load and stopping the drive motor was automatically triggered, simultaneously locking all parameter test data at the moment of the anomaly.

[0048] After calibration, simulated loads were applied step-by-step according to the test condition matrix to conduct full-condition load performance tests. First, stable operation tests under low load conditions were completed, then the load was gradually increased to the rated load condition. The system was then continuously operated under the rated load stable condition for 60 minutes, continuously collecting the gearbox's input and output torque, real-time speed, vibration spectrum, housing temperature distribution, and transmission noise parameters. Subsequently, dynamic variable load condition tests were performed, acquiring dynamic response characteristic data during load jumps and speed abrupt changes. Simultaneously, abnormal impact signals during the transmission process were recorded, and spectral analysis of the vibration signals was performed to identify fault characteristics such as abnormal gear meshing, bearing wear, and shaft misalignment during the gearbox transmission process.

[0049] The gearbox under test, along with its adapter, was then placed in a high-low temperature environment chamber for environmental adaptability testing. The test simulated the actual working environment of the inspection drone at high altitudes (-40℃) and Gobi Desert (60℃). The temperature change rate during the high-low temperature cycle was controlled at 2℃ per minute, and the holding time at each temperature point was 2 hours. After ensuring the overall temperature of the gearbox reached the set value, the rated load performance test was repeated. Data on the changes in transmission efficiency and the impact of thermal deformation on transmission accuracy under different ambient temperatures were collected. Simultaneously, the viscosity change and lubrication status of the lubricating oil inside the gearbox were monitored.

[0050] At the end of the testing phase, based on the test data collected under all operating conditions, a quantitative evaluation of the gearbox's comprehensive transmission performance was completed. Transmission efficiency, load holding capacity, transmission accuracy stability, vibration and noise levels, and environmental adaptability indicators were calculated under all operating conditions. A comprehensive performance score was obtained through multi-dimensional weighted calculation. A 500-hour fatigue durability cycle test was performed. The cycle test conditions adopted the typical flight mission load spectrum of the inspection drone. The duration of a single cycle was consistent with the duration of a single inspection flight of the drone, and the total number of cycles was not less than the total number of flights within the drone's design lifespan. During the test, a benchmark performance test of the gearbox was performed every 50 hours, recording the attenuation and change patterns of transmission performance, and constructing a predictive model for the full life-cycle degradation trend of the gearbox's transmission performance. After the test, the gearbox was disassembled, and the wear and fatigue damage of the gears, bearings, and shafts were inspected. Finally, a standardized transmission performance test report was output.

[0051] Table 2: Performance Comparison of This Method and Traditional Testing Methods for Inspecting the Gearbox of UAVs

[0052] Table 2 clearly demonstrates the comprehensive advantages of this method in the testing scenario of gearboxes for long-endurance industrial inspection drones. Traditional testing methods mostly focus on short-term rated load performance testing, failing to simulate the continuous long-endurance operation of inspection drones. They also lack sufficient coverage for performance testing in extreme high and low temperature environments and a robust test safety protection mechanism. This method, tailored to the operational characteristics of inspection drones, sets up long-duration stable operating condition tests, fully covering performance verification in extreme environments such as high-altitude and frigid zones. Through high-precision testing and end-to-end safety interlocking, it comprehensively verifies the long-endurance operational stability and reliability of the gearbox, adapting to the full-scenario testing needs of industrial inspection drones.

[0053] Reference Figure 1 This diagram illustrates the complete lifecycle of high-torque gearbox transmission performance testing for UAVs from a macro perspective. The process begins with hardware preparation before testing, including customized fitting fixtures, rigid bench mounting, and high-precision laser alignment calibration. Then, the core testing chain is entered, sequentially performing no-load benchmark performance tests to complete pre-loss calibration, applying multi-dimensional simulated loads for rated and dynamic response tests, and moving the system into a high- and low-temperature environmental chamber to verify transmission stability under extreme temperatures. After acquiring full-condition data, the system performs a comprehensive quantitative evaluation of transmission performance and long-term fatigue durability cycle testing, ultimately outputting a standardized report, forming a closed-loop, rigorous testing system.

[0054] Reference Figure 2This diagram highlights how the testing system translates the actual flight missions of the UAV into specific execution states on a physical test bench. The system first analyzes real flight scenarios such as hovering, constant speed cruise, high-G maneuvering, gust resistance, and vertical takeoff and landing, mapping them to different gradients of speed and torque commands. During the test execution phase, the state machine flexibly switches between rated load stable conditions, load step change conditions, and extreme overload conditions, with strict loading rates and gradients set. This multi-state transition mechanism ensures that the test cases fully cover the complex alternating force conditions of the UAV in the air, comprehensively verifying the gearbox's shock resistance.

[0055] Reference Figure 3 This diagram details the hardware and software data compensation logic designed to improve testing accuracy. Since the bearings, air resistance, and couplings of the test bench itself inevitably generate power losses, the system performs a no-load benchmark calibration across the entire speed range before officially mounting the gearbox, quantifying the comprehensive air resistance and friction loss coefficients at different speeds. In the subsequent load-bearing test, the system reads the speed data in real time and uses the pre-calibrated loss model for dynamic calculation, accurately separating the inherent losses of the test bench from the measured total power, thereby outputting clean and accurate gearbox transmission data and significantly eliminating system errors.

[0056] Reference Figure 4 This diagram illustrates the intelligent evaluation and analysis architecture for post-processing of test data. The underlying layer aggregates massive amounts of test data across five core dimensions: transmission efficiency, transmission accuracy, vibration and noise, environmental adaptability, and reliability / lifespan. The system uses a pre-defined dynamic weighting system to weightedly couple and calculate these heterogeneous data, generating an intuitive overall transmission performance score to facilitate the grading and finalization of different batches of products. Simultaneously, a predictive model based on fatigue cycle test attenuation data is introduced as a bypass to extrapolate the performance degradation trend and safe operating threshold of the gearbox throughout its entire lifespan, directly providing a scientific basis for UAV flight path planning and periodic maintenance.

[0057] Reference Figure 5 This diagram focuses on the highly reliable security defense mechanism at the bottom layer of the testing system. Equipment safety is paramount during prolonged, high-intensity extreme overload and fatigue testing. The monitoring system scans the output power of the drive motor, the triaxial vibration amplitude of the gearbox, the temperature rise rate of the housing, and the load status of the magnetic powder unit in real time at millisecond-level parallel scans. Once the logic judgment center detects that any data in any dimension exceeds the set safety threshold, the system will instantly trigger hardware cascade protection actions, automatically performing step-by-step load unloading and flexible motor deceleration shutdown according to a preset sequence, and locking the complete data record at the moment of the fault, fundamentally preventing destructive damage.

[0058] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for testing the transmission performance of a high-torque reduction gearbox for unmanned aerial vehicles (UAVs), characterized in that, Includes the following steps: Customized tooling was designed based on the installation interface and dimensions of the high-torque reduction gearbox of the UAV under test. The reduction gearbox was fixed on a rigid test bench. The coaxial connection of the drive servo motor, torque and speed sensor and magnetic powder load device was completed. The coaxiality of the drive end, reduction gearbox and load end was calibrated by laser alignment instrument. The installation and signal calibration of vibration, temperature and noise sensors were completed simultaneously. The benchmark parameter file of the test system was established. Based on the actual load of the UAV in all flight conditions, a multi-dimensional test condition matrix is ​​constructed, covering the speed and torque load conditions under different flight modes. The test duration, load loading rate and speed change gradient of each condition are set, and the test data acquisition frequency and key acquisition nodes are determined. The drive motor is controlled to perform a step-by-step speed increase and decrease cycle according to the preset no-load speed gradient. No-load transmission torque, input-output speed difference, vibration acceleration, operating noise and shell temperature parameters are collected. The no-load transmission efficiency, return clearance and no-load power loss benchmark values ​​are calculated to complete the pre-calibration and elimination of the transmission loss of the test system itself. Simulated loads are applied step by step according to the test condition matrix. Input and output torque, real-time speed, vibration spectrum, shell temperature distribution, and transmission noise parameters of the gearbox are collected under the rated load stable condition. Dynamic response characteristic data of load step and speed change are collected under dynamic load condition. The gearbox under test was placed in a high and low temperature environment chamber to conduct high and low temperature environment adaptability test, simulating the actual working environment of UAV with high altitude low temperature and near ground high temperature. The rated load performance test was repeatedly performed under the set high and low temperature cycle conditions, and the data on the transmission efficiency change and the influence of thermal deformation on the transmission accuracy of the gearbox under different ambient temperatures were collected. Based on the test data collected under all operating conditions, the comprehensive transmission performance of the gearbox is quantitatively evaluated. The transmission efficiency, load stability, transmission accuracy, vibration and noise characteristics, and environmental adaptability under all operating conditions are calculated. Fatigue durability cycle tests of a set duration are performed, and a standardized transmission performance test report is finally output.

2. The method for testing the transmission performance of a high-torque reduction gearbox for unmanned aerial vehicles according to claim 1, characterized in that, It also includes precise calibration and dynamic compensation steps for transmission losses in the test system. Before the no-load benchmark performance test, the no-load loss calibration of the test bench in the full speed range without a gearbox is completed, and the comprehensive loss calculation formula of the test bench system is introduced: ； in To test the overall transmission loss power of the test bench system at the corresponding speed, For the test bench Level test speed, This represents the drag loss coefficient at the corresponding rotational speed. This represents the bearing friction loss coefficient at the corresponding rotational speed. This represents the fixed loss coefficient of the coupling at the corresponding rotational speed. This represents the total number of levels of the test rotational speed gradient.

3. The method for testing the transmission performance of a high-torque reduction gearbox for unmanned aerial vehicles according to claim 1, characterized in that, It also includes a step to predict the degradation trend of gearbox transmission performance throughout its entire life cycle. After completing basic performance tests and fatigue durability tests, a gearbox transmission performance degradation prediction model is constructed based on performance decay data from different cycle periods to predict the performance decay pattern and service life threshold of the gearbox during the actual flight of the UAV.

4. The method for testing the transmission performance of a high-torque reduction gearbox for unmanned aerial vehicles according to claim 1, characterized in that, It also includes multi-dimensional safety interlock protection steps throughout the entire testing process. During the test, the power of the drive motor, the vibration amplitude of the gearbox, the housing temperature, and the load parameters of the load device are monitored in real time. When any parameter is detected to exceed the preset safety threshold, the protection process of gradually unloading the load and stopping the drive motor is automatically triggered, and the full parameter test data at the moment of the abnormality is locked simultaneously.

5. The method for testing the transmission performance of a high-torque reduction gearbox for unmanned aerial vehicles according to claim 1, characterized in that, In the coaxiality calibration step, the calibration accuracy of the laser alignment instrument is controlled within 0.02mm, the radial runout deviation of the drive end, gearbox, and load end is controlled within 0.05mm, and the end face runout deviation is controlled within 0.03mm. After calibration, the rigid connection of each component is completed through a high-strength coupling. At the same time, the levelness of the test bench is calibrated, and the levelness deviation of the bench plane is controlled within 0.02mm / m.

6. The method for testing the transmission performance of a high-torque reduction gearbox for unmanned aerial vehicles according to claim 1, characterized in that, In the step of constructing a multi-dimensional test condition matrix, the test duration of the rated load condition is no less than 30 minutes, the number of load step changes in the variable load dynamic condition is no less than 20, the gradient of the speed change covers the entire range from 0 to the rated speed during the flight of the UAV, and at the same time, at least 3 sets of extreme overload conditions are set, and the extreme load torque is no less than 1.5 times the rated torque of the gearbox.

7. The method for testing the transmission performance of a high-torque reduction gearbox for unmanned aerial vehicles according to claim 1, characterized in that, In the steps of the quantitative evaluation of the comprehensive transmission performance of the gearbox, a multi-dimensional weighted comprehensive performance scoring formula is introduced: ； in The overall score represents the comprehensive transmission performance of the gearbox under test. Standardize the scoring for the transmission efficiency dimension. Standardized scoring for transmission accuracy dimension. Standardize the scoring for the vibration and noise dimension. Standardize the scoring for the environmental adaptability dimension. Standardize the scoring for the reliability and lifespan dimension. , , , , These are the weight coefficients for the corresponding dimensions, and the sum of all weight coefficients is 1.

8. The method for testing the transmission performance of a high-torque reduction gearbox for unmanned aerial vehicles according to claim 1, characterized in that, During the acquisition of vibration acceleration parameters, a triaxial accelerometer is used for vibration detection, which is respectively installed at the input shaft end, output shaft end, and middle of the gearbox housing; during the acquisition of operating noise parameters, a microphone is used for noise detection, which is placed 1 meter away from the gearbox housing. Spectral analysis of the test data was performed to identify fault characteristics such as abnormal gear meshing, bearing wear, and shaft misalignment.

9. The method for testing the transmission performance of a high-torque reduction gearbox for unmanned aerial vehicles according to claim 1, characterized in that, In the fatigue durability cyclic test, the cyclic test conditions adopt the load spectrum of a typical UAV flight mission. A single cycle includes the entire process of no-load start-up, rated load operation, overload impact, and deceleration shutdown, with the duration consistent with the typical flight duration of a single UAV flight. The total number of cycles is not less than the total number of flights within its design service life. A benchmark performance test is performed at fixed intervals of cycles to record the transmission performance decay pattern. After the test, the gears, bearings, and shafts are disassembled and inspected for wear and fatigue damage.

10. The method for testing the transmission performance of a high-torque reduction gearbox for unmanned aerial vehicles according to claim 1, characterized in that, In the high and low temperature environment adaptability test, the low temperature test environment temperature is set to -40℃, the high temperature test environment temperature is set to 60℃, the temperature change rate during the high and low temperature cycle is controlled at 2℃ per minute, the heat preservation time at each temperature point is not less than 2 hours, and the performance test is performed after the gearbox as a whole reaches the set temperature; the internal lubricating oil viscosity change and lubrication status are monitored simultaneously to evaluate the comprehensive impact of extreme temperature on the lubrication system and transmission performance.

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