Research On Nonliner-dynamic Modeling Technology For Unmanned Helicopter

Unmanned helicopter not only has the characteristics of small size,light weight and low cost,butalso has the special flighting ability such as vertical take-off and landing,hovering and low attitudeflight and so on.Therefore,Unmanned helicopter has broad application prospects whether in thecivilian field or in the military field.However,the helicopter itself is a highly non-linear,strongcoupling and instability system,what’s more,the study of a control system is based on a high accuracymodel.So the research of dynamic model of unmanned helicopter has important theoreticalsignificance and practical value.The unmanned helicopter is a multi-body dynamics system including the main and the tailrotor,fuselage,vertical tail and horizontal tail and so on.The model of the rotor refers to theaerodynamic model of the blades,the waving motion model and the induced velocity model.Thispaper proposes an equivalent approach to build the model of the rotor based on the features the Vortextheory and the blade element theory.The induced velocity model of the disk and the induced velocitymodel are got by studying the downwash of the rotor,and the motion equations of waving are got bythe Plasma disk plane method.For other pneumatic components,we still use the trantional method tobuild these models.The course of implementation of the model,the force and moment of infinitesimalelement is calculated by using the overall and local compromise method,the downwash field of therotor is described and the waving angle is calculated through the normal distribution,then the forceand the torque of the whole rotor and other components is abled to be obtained by summation in orderto establish the aerodynamic model of the unmanned helicopter.At the same time,the correctness andavailability of the model are verified from the algorithm and the characters of the model.Finally,on the basis of the model,the simulation environment of the dynamics model is built byusing the technology of RTX in the Windows.This system is composed of two parts.The front desk isa simulation console which is created by the TRTD and the main function is to display real-timesimulation parameters,the track of airlines as well as the historical curve.The background is thereal-time model of simulation based on the RTX,which is mainly used for the slover of the model ofthe unmanned helicopter.Through the system integration and the flighting control simulation,thevalidity of this model is verified and the target of the topic is achived.