Altitude control system of autonomous airship based on fuzzy logic

A kind of design method of compound control system is proposed based on fuzzy logic control, according to the problem of altitude control for unmanned autonomous airship. By considering the scheme of buoyancy control system in the airship, the flight kinematics model is established based on forces acted on the airship. During the longitudinal movements, the altitude control system is separated into two parts with the velocity control subsystem and the altitude control subsystem. The whole altitude control system is designed by fuzzy control theory, in which the fuzzy logic is used to adjust the controller by fuzzy inference rulers in different conditions. In order to prove the correctness of the feasibilities of the altitude control strategy, a simulation system with the whole control model is established. At the same time, an illustrative example is given to show that proposed compound control scheme can make unmanned autonomous airship ascent in expected velocity and reach in expected altitude, which is robust to parametric perturbations and external disturbances.