I&I-based adaptive control of a four-rotor mini helicopter

For a four-rotor mini helicopter, an adaptive controller is presented based on Immersion and Invariance (I&I) approach. Although there are many aerodynamic coefficients such as thrust coefficients and drag coefficients with uncertainty in the model, a new parameterization with a fewer uncertain coefficients is developed to simplify the complex multivariable parameter adaptation. It is shown that the adaptive controller is capable of estimating not only the unknown parameters but also external torque disturbances and rejecting them. Numerical simulation illustrates the robustness of the controller against the parametric uncertainty and external torque disturbances.