| In recent years,China’s plant protection UAV industry has developed rapidly,in which electric multi-rotor UAV accounts for the largest proportion.As the main application field of current UAV technology industry,electric multi-rotor UAV can be used for spraying pesticide,fertilizer,herbicide,aerial seeding,auxiliary pollination and many other fields.However,at present,there is a lack of perfect and standard technical standards and operation specifications in the field of electric multi-rotor UAV.Although some group standards have been issued,the corresponding index test methods are not detailed enough to be standardized,and the impartiality of evaluation indexes still needs to be further studied.Therefore,how to establish a scientific and comprehensive UAV evaluation system and electric multi-rotor UAV performance testing system,and test and demonstrate its key indicators is one of the difficulties in the current safe use and large-scale promotion of electric multi-rotor UAV.Electric multi-rotor UAV is the mainstream model applied in the field of agriculture at present,accounting for more than 80% according to statistics.In this paper,the performance testing platform of electric multi-rotor UAV is designed,and the evaluation method of lift characteristics is studied,and the important indexes of lift characteristics and safety performance are tested and demonstrated.The main research contents and results are as follows:(1)More than the existing electric rotor UAV for investigation and statistics,all models mainly four rotor,rotor six and eight rotor UAV is given priority to,the largest quality is 65 kg,maximum size of the whole machine is 4040 mm,maximum voltage of 50.4 V,considering the above electric rotor parameters of u UAV,the existing test platform for the improvement and optimization,considering electric UAV rotorcraft more safety and reliability requirements,adopt aluminum alloy truss,adjust the slide rail,hydraulic shock absorber,limit three limit,dc power supply,wire rope hanging code,the infrared thermal imager,lift test equipment or devices such as,Design for more than half a tie-down type electric rotor UAV performance test platform,with different types,different specifications of the electric rotor UAV for testing,can good process of UAV real flight simulation,and can effectively guarantee the rotor UAV is not damaged in the process of the limit test,and the shock absorber and spacing device has carried on the finite element analysis and dynamic analysis,according to the analysis results meet the requirements of the current test,finally using the Lab VIEW software design more than electric rotor unmanned aerial vehicle performance testing software system.By testing the current,voltage,effective lift,motor surface temperature,attitude and other parameters of the electric multi-rotor UAV in flight,the test system can collect the parameters of the electric multi-rotor UAV in flight in real time.(2)In order to have a unified evaluation standard for the temperature rise test of the motor under different ambient temperatures,the comparative tests of different brushless motors under different ambient temperatures were carried out in the artificial climate box.The results of the infrared thermal imager measurement and the contact measurement were compared to determine the emissivity of the brushless motor at 0.91.Secondly,the motor wrapped with different materials is used for the comparative test of temperature rise,and the difference of different surface temperatures is significant.Finally with ambient temperature as the temperature rise is verified the rationality of the evaluation standards,and to ask in a different environment test,compared with the real result,temperature of 0.5 ℃,satisfy the requirement of the temperature rise test.(3)Through the analysis of the principle of the electric multiple rotor unmanned aircraft power system,from energy consumption,load,the working process of the heat from three angles,is put forward to power load,the weight ratio of efficiency and thermal efficiency of electric multiple UAV rotorcraft lift evaluation method,the characteristic of the different models of total net lift,lift,efficiency of power load,weight,temperature change were analyzed,and the selection of more than three electric rotor UAV,the lift test results respectively 246 n,363 n and 269 n,three models of maximum power load of 59.2 m N/W,63.2 m N/W and 69.3 m N/W,maximum weight efficiency is 1.29,0.96 and 1.15,the results of tests under different ambient temperature for correct processing,calculation of the three models of thermal effect of ratio were 124.8 N / ℃,121.8 N / ℃ and 130.6 N / ℃.(4)Based on the stability analysis method of electric multi-rotor UAV,from the three angles of roll angle,pitch angle and height,combined with the characteristics of hovering stability of electric multi-rotor UAV,lateral stability and longitudinal stability are proposed.The evaluation method of hovering stability of electric multi-rotor UAV based on the performance and high stability is discussed,and the lateral stability,longitudinal stability and high stability of different models are discussed and analyzed,and electric power can be passed through this test platform.The multi-rotor drone is tested with high precision.(5)On the basis of the above performance testing platform,the application test and demonstration of the performance index evaluation of the electric multi-rotor UAV were carried out through the application demonstration,the important indexes of lift characteristics and hover stability were evaluated,and the corresponding improvement suggestions were put forward. |
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