Structure Design And Optimization And Modeling Of Small Ducted Fan UAV With Gas Power

The speed development of Smart City provide much chance to develop movableplatform for sensing detection system, the ducted fan UAV with gas power which canmobilize rapidly,spot hover and has longer flying time and safety has become the bestchoice of this field. But the complex structure of this kind of UAV, and the technology ofstructure design, aerodynamic characteristic and model control has not been mature, sothere isn’t extensive applyment of this kind of UAV. For these problem, this essay doessome research about structure design, dynamic model and optimizing design of ducted fanUAV.The ducted fan UAV with gas power for civil using is different with for military one,thinking the applying background of Smart City and refer the performance of militaryducted fan UAV, this paper set the technology target of the UAV which would be researched.The overall arrangement of ducted fan UAV has diversity, special the project of attitudecontrol mechanism, this paper confirm the control mechanism scheme by fuzzy evaluationmethod. Then designing the sub-system of ducted fan UAV: with comparison ofperformance, the power source select Zenoah80cc engine, and we do much test for thesituation that the different propeller working with Zenoah80cc engine, select the propellerwhich has three impellers as the partner of this engine. Nextly, the paper designs ductstructure and selects the material type, does the modal analysis for the mounting rack,confirm the modal frequency of mounting rack isn’t same with the vibration frequency ofengine. The paper designs the structure of anti-torque flap and control flap by mathematicalcalculation and CFD simulation. Selecting two common kind of undercarriage as thebackup plan of ducted fan UAV, and analyzing the impulsive load and dynamic processwhen the UAV installed two kinds of undercarriage is falling down from2m height,confirm the optimizing project of undercarriage. After finish all of design, this paper showthe photo of prototype.The ducted fan UAV is a kind of statically unstable aircraft, we should build theaccurate mathematic model before design the control algorithm, and recognize the constantparameter of mathematic model. This paper research the force analysis of sub-system ofducted fan UAV, then build the mathematic model of ducted fan UAV with the analysismethod of rigid body dynamic. After analyzing the model, this paper concludes theparameters which need to be recognized, then confirm the occurrence of these parameters with a series of methods.After the design of ducted fan UAV and analysis of mathematic model, this papercomes up with a kind of structure optimizing scheme of ducted fan UAV: realizing thecontrol of UAV with differential motivation of only four control flaps. With the method ofANSYS CFX simulation, this paper does a comparison between original structure schemeand optimizing scheme, verifying the feasibility of aerodynamic property. Then this paperbuilds the mathematic model of optimizing scheme, and analyzes the zero dynamic of thesystem and proves the stability of the system. Lastly, this paper design a kind of optimalquadratic controller, and verifying the feasibility of practical control of optimizing modelwith matlab simulation.