The Overall Design And Energy Efficiency Optimization Of The Solar-Powered Unmanned Aerial Vehicle Based On Balloon-borne Launch

Due to the environmental pollution caused by traditional fossil energy,the future development of power machinery that uses fossil energy as a power source will pay more attention to the development and utilization of new energy.Solar energy is an inexhaustible new type of clean energy,and power machinery using solar energy as a power source will be one of the key directions of future development.The High-Altitude Long-Endurance(HALE)Solar-Powered Unmanned Aerial Vehicle(SP-UAV)is a combination of UAV technology and solar power technology.It uses photovoltaic cells and energy storage batteries as the energy system,realizes ultra-long endurance flight through the comprehensive utilization of solar energy.SP-UAV has the ability to fly continuously across the day and night or even across the month.Since SP-UAV has the ability to fly for a long time,it can be used as an aerial application platform in near space.Compared with satellites,SP-UAV can achieve higher resolution informa-tion acquisition,communication relay,and realize information integration,transmission and distribution in near space,which has a broad application prospect.However,the multidisciplinary research of SP-UAV involves multiple frontier fields of scientific and engineering research,covering a number of difficult frontier technologies such as over-all technology,structural lightweight technology,renewable energy technology,low Reynolds number aerodynamic layout technology,which leading to slower develop-ment of SP-UAV.Therefore,in order to break through the key bottleneck of SP-UAV under the existing technical conditions,this paper carried out the overall design and tra-jectory planning research of the SP-UAV based on the mission-oriented,and optimized the energy efficiency of the SP-UAV through the combination of the two technologies.The main research work and innovation points of this paper are as follows:Research on overall design of SP-UAV based on optimization of flight profile.Us-ing the innovative method of ball-borne take-off and high-altitude launching,combined with the joint-wing layout that meets the requirements of omnidirectional mission de-tection,the overall design research of HALE SP-UAV is carried out.Firstly,a multi-disciplinary model with energy as the core is established to analyze the design feasible region of SP-UAV that use gravitational potential energy storage as the energy manage-ment strategy,and to study the coupling between the overall design based on energy balance and the flight profile.Secondly,on the basis of traditional design methods,the flight profile optimization is integrated into the top-level design of SP-UAV.According to the typical mission requirements of SP-UAV,considering the design variables and target values such as wing area,aspect ratio,sunshine conditions,etc.Multi-objective optimization is carried out according to the algorithm,and then the evaluation func-tion is used for optimization.Finally,the optimal SP-UAV overall parameter matching scheme is selected.Research on innovative solutions for SP-UAV launch methods based on ball-borne takeoff and high-altitude launch.First of all,in view of the difficulties in the process of large aspect ratio SP-UAV taking off and climbing to the near space,which requires high requirements on the propulsion system and the landing field.The method of launching SP-UAV with balloon-borne is proposed,that is,the SP-UAV is carried to the near space by high-altitude balloon-borne for launching.This approach can effectively re-duce the requirements on the take-off field and avoid the propulsion system operating at high power deviations from the design point for a long time.Secondly,the impact of the launching attitude,rudder deviation and thrust on the launching process is studied through simulation experiments,and the boundary conditions of the launching process are preliminarily obtained.Under the guidance of the simulation tests,the launching test design of the launching system is carried out and the scheme design of the launch-ing system is completed.Finally,the feasibility and the optimal angle of balloon-borne launching are verified by many tests.Research on SP-UAV trajectory planning technology with energy efficiency optimization in typical high altitude long endurance application environment.Aiming at the characteristics that the endurance performance and mission performance of SP-UAV are closely related to the flight path,and to solve the problem that the current research on flight path planning is lack of typical mission scenarios for SP-UAV,a large-span space-time mission scenario based on the ultra-long flight duration of SP-UAV is proposed.Based on this particular scenario,an energy management strategy based on gravitational potential energy storage is adopted to solve the problem of flight path optimization un-der this scenario.Combining the mission path planning method with the trajectory optimization method of energy management strategy,a multi-objective joint algorithm is used to solve the complex coupling problem considering both mission constraints and energy optimization.Research the trajectory planning technology of SP-UAV in large-span space-time scenarios,and provide guidance for the trajectory planning of SP-UAV performing target search missions in this scenario.Research on multi-aircraft collaborative path planning of combined SP-UAV based on the combination of SP-UAV technology and swarming technology.Aiming at the problems of low mission efficiency,low reliability and difficult take-off and landing of the existing SP-UAV,a new idea of combined SP-UAV is put forward in combination with the idea of modular cluster UAV.By studying the mission-oriented multi-aircraft cooperative three-dimensional flight path planning of the combined SP-UAV under the condition of limited solar irradiation,the overall model of the combined SP-UAV is designed,and the multi-stage flight strategy of the combined SP-UAV is studied,so as to solve the combinatorial optimization problem under the large-scale multi-coupling constraints.To sum up,in order to maximize the energy efficiency of SP-UAV,this paper car-ried out research on the overall design and flight trajectory planning technology of SP-UAV.Firstly,the overall design method and technical scheme of SP-UAV are proposed according to the mission requirements.Secondly,the feasibility of balloon-borne launch and the optimal launch conditions are verified.Then,according to the characteristics of SP-UAV,the optimal flight trajectory planning is studied.Finally,the related research on the cooperative path planning of the combined SP-UAV is carried out.The research work can provide a reference for the theoretical research and engineering design of SP-UAV,and provide ideas and directions for the development of SP-UAV in the future.