  In this paper, a combination of fuzzy clustering estimation and sliding mode
control is used to control a quadrotor system, whose mathematical model is
complex and has unknown elements, including structure, parameters, and so on.
In addition, they may be affected by external environmental disturbances. At
first, the nonlinear unknown part of the system is estimated by a fuzzy model,
A new method is presented for constructing a Takagi-Sugeno (TS) interval-valued
fuzzy model (IVFM) based on inputoutput data of the identified system.
Following the construction of the fuzzy model that estimates the unknown part
of the quadrotor system, a control and on-line adjusting of the fuzzy modeled
part of dynamics is used. In this step, the system model will be estimated in
adaptive form so that the dynamic equations can be used in sliding mode
control. Finally, the proposed technique is applied, and the simulation results
are presented to show the effectiveness of this approach in controlling the
quadrotor with unknown nonlinear dynamics.
