Dynamic Modeling and Motion Stability Analysis of Tethered UAV

Tethered unmanned aerial vehicle (TUAV) is unstable due to some uncertain factors such as wind interference and tension of the tether. For solving above issues, a stability analysis method based on Lyapunov exponents is introduced. Firstly, the catenary theory and the Euler-Lagrange method are formed to establish the model of the tether and UAV respectively, combining two models to obtain the dynamical model of TUAV. Then Lyapunov exponents method is used to construct the quantitative relationship. Finally, the stability is verified by the flight test of the physical prototype. Results show that: 1) in a certain range, the larger the propeller radius is, the better the flight stability of the system is; 2) in the landing phase, the higher the initial speed of the landing motor is, the better the stability of the tethered unmanned aerial vehicle is.