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A quaternion-based feedback is developed for the attitude stabilization of rigid bodies. The control design takes into account a priori input bounds and is based on nested saturation approach. It results in a very simple controller suitable for an embedded use with low computational resources available. The proposed method is generic not restricted to symmetric rigid bodies and does not require the knowledge of the inertia matrix of the body. The control law can be tuned to force closed-loop trajectories to enter in some a priori fixed neighborhood of the origin in a finite time and remain thereafter. The global stability is guaranteed in the case where angular velocities sensors have limited measurement range. The control law is experimentally applied to the attitude stabilization of a quadrotor mini-helicopter.

International audienceThis paper proposes a distributed control scheme to regulate the power flows among multiple microgrids operating in islanded mode. Each microgrid controller gathers information from neighboring microgrids and reduces dynamic interactions. Modal analysis and time-domain simulations are used to identify critical issues that degrade the stability of microgrids under different operating conditions. A case study comprising three interconnected microgrids is considered. Each microgrid includes distributed generation and is described through a detailed dy- namic model. Time-domain analyses are carried out considering different scenarios and large disturbances. Simulation results indicate that, while conventional controllers can lead to poorly damped power oscillations among the interconnected microgrids, the proposed control scheme guarantees stability in the post- disturbance operating conditions