Research On The Design Of Small Tilt Rotor And Its Tilt Stability

At present,most of the aircrafts are fixed-wing and multi-rotor.Fixed-wing aircrafts fly forward in high speed,long endurance and large payload.However,they cannot take off and land vertically,an appropriate runaway is required.On the other hand,multi-rotors are capable of taking off and landing vertically,as well as hovering at a fixed point to complete special tasks,but their flight speed are slow and endurance are short comparing to fixed wing plane.In order to get better flight performance,in this article we design and implement an aircraft called tilt-rotor which combining the advantages of multi-rotor and fixed wing,the aircraft can satisfy vertical take-off and landing and also achieve flying at a high speed for long time.Compared with multi-rotor and fixed-wing,tilt-rotor aircraft has a broader application prospect.The main content of this paper is the design of the tilt rotor and the stability of the tilt transition.Firstly,based on the existing experimental conditions and task,we estimate the weight of the tilt rotor aircraft,then the overall layout of the tilt rotor aircraft is designed through detailed consideration on the structural characteristics of the quad rotor,fixed wing,and tilt quad rotor aircraft.According to the estimated weight and flight speed requirements of the aircraft,the overall parameters such as the airfoil profile,wing area,span,and rotor radius of the aircraft are preliminarily determined.According to the above parameters,the configuration of the tilt rotor aircraft components and the power system are further designed in detail.Secondly,on the basis of the designed aircraft,we establish a suitable coordinate system in order to analyze the forces and moments of the tilt rotor aircraft.The Newton-Euler equation is used to build its dynamics and kinematics models.Then we make appropriate assumptions about the tilt rotor aircraft and simplify its dynamics model to facilitate research and calculation.When designing the controller,we build the tilt rotor simulation control module with simulink,and verify the stability of rotor mode,fixed wing mode and transition mode.Through simulation analysis and optimization of the tilt rotor transition process,we achieve better distribution of rotor control and surface control in the transition process,ensures a smoother transition of the aircraft.Finally,the verification machine is made based on the designed tilt rotor aircraft,and adjusted through ground tests to ensure that the verification machine is free of faults.We have performed outdoor flight test of the rotor mode,fixed-wing mode and transition mode of the aircraft,and verified the controllability and stability of the verification machine.Then based on data collected from flight test,we have optimized the transition stage by adapting and improving the verification machine,and made the second generation verification machine.