Research On Design Method And Characteristic Law Of Hybrid Propulsion VTOL UAV

Hybrid propulsion VTOL UAVs are widely employed in many various spheres of society because to their low energy consumption,extended trips and flying duration,and heavy load.Traditional hybrid propulsion VTOL UAVs,on the other hand,have intrinsic limitations like as short vertical maneuvering time,low energy usage,and limited power redundancy,which limit their application situations.They can only navigate vertically for a short length of time,making them unsuitable for commercial applications such as accurate electrical inspections that require the UAV to hover for a sustained period of time.The problems in the UAV power system are the principal source of the aforementioned issues.This thesis provided a direct-drive hybrid propulsion VTOL UAV with a direct-drive hybrid power system in conjunction with the VTOL UAV application requirements and hybrid power system characteristics.VTOL UAV with direct-drive hybrid power and its power system design method were investigated during the study process,with the target UAV described as a long-endurance,low-speed,medium-altitude small UAV with a takeoff weight of 20 kg class.In addition,the power configuration laws and energy flow patterns of the power system in the target UAV’s flying envelope were investigated.The thesis is organized as follows:(1)Based on an analysis of the hybrid system’s features and the needs of the application elements of the VTOL UAV,a direct-drive hybrid system topology suitable to the VTOL UAV was presented.Moreover,the needs of the application aspects of the VTOL UAV were integrated with the development requirements,and an initial design plan and technical performance parameters for the direct drive hybrid propulsion UAV were presented.(2)Investigated direct-drive hybrid power systems and ground test bench design method.A ground test bench was developed to explore the features of the direct-drive hybrid power system,with emphasis on hardware fabrication and software development.The creation of mechanical design,lower computer of the measurement and control system,and upper computer of the human-computer interface were finished by analyzing the functional requirements of the ground test bench.(3)The characteristics of a direct-drive hybrid power system were investigated.The integrated text approach of power system characteristics was developed,which employs an experimental modeling approach to generate power system characteristic diagrams and curves based on test data.On this basis,a numerical simulation model of the steady-state and dynamic properties of the direct-drive hybrid power system were developed.Finally,Based on a two time test approach to validate the feasibility of the test method and the accuracy of the model.(4)Finished the design of a direct-drive hybrid propulsion VTOL UAV flight test platform(prototype)and studied the design approach of the direct-drive hybrid propulsion VTOL UAV which integrate with the basic design plan and technical performance index criteria.Picked a suitable fixed-wing fuselage which was added a multi-rotor section depending on the goal takeoff weight.While designing the layout of the power plant,propulsion system,avionics and control system,and ultimately the weight calculation of the full prototype was completed.(5)The flight operating mode of the direct-drive hybrid propulsion VTOL UAV in the whole flight profile was explained based on the features of the UAV,and the usual flight operating mode is appropriately developed to increase the UAV’s dependability and energy consumption.Finally,The ground and aerial flight tests of the direct-drive hybrid propulsion VTOL UAV validate the structural and control systems’ durability,as well as the overall flying performance of the UAV prototype.Moreover,the flying characteristics of the direct-drive hybrid propulsion VTOL UAV are studied,providing a solid foundation for the design and development of direct drive hybrid propulsion VTOL UAVs.The general design and characteristics law technique of the direct-drive hybrid power system,as well as direct-drive hybrid propulsion VTOL UAV with direct-drive hybrid power,were investigated in this study.Furthermore,the strategy has been demonstrated to be viable and successful.They are able to give a reference for the design of hybrid propulsion VTOL UAVs with more functional modes and a wider variety of applications.