An original configuration of a small aerial vehicle having eight rotors is presented. Four rotors are devoted to the stabilization of the orientation of the helicopter, and the other four are used to drive the lateral displacements. A precompensation on the roll and pitch angles has been introduced so that the attitude dynamics is practically independent of the translational dynamics. This compensation is directly related to the velocity of the lateral motors. The dynamical model is obtained using the Euler–Lagrange approach. The proposed configuration is particularly useful for image processing since the the camera orientation is held constant. The eight-rotor rotorcraft is simpler to pilot than other rotorcrafts. A control strategy is proposed that uses the optical flow measurements to achieve a hover flight that is robust with respect to perturbations like wind. The new aerial configuration and control strategy have been tested in real-time experiments.

In this paper we present the dynamic model and the stabilisation of an original configuration of an small helicopter having eight rotors. This configuration is not yet presented in the literature and in our knowledge is also the first prototype of this kind of helicopters. The equations of motion for the VTOL aircraft are obtained using Euler-Lagrange approach. Due to the configuration of the aircraft the attitude dynamics are practically independent of the translational dynamics corresponding to the lateral displacements (x and y). A nonlinear control strategy based in the Lyapunov analysis is proposed to stabilize this aircraft at hover. The performance of the nonlinear control algorithm is illustrated with real-time experiments.