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.

Event-triggered control is a sampling strategy that updates the control value only when some events occur. An event is usually generated by an event-function that indicates if the control signal must be updated or not. If one excepts self-triggered implementation, event-triggered control requires the evaluation of the event function at each time instant. Unfortunately, in the literature of nonlinear system event-based control, computing the event function is more resource consuming than computing the control itself. Moreover, it requires the knowledge of a Lyapunov function that is not necessarily available. The purpose of this paper is to propose for affine nonlinear systems a new strategy for the choice of the event function that only requires the computation of the control. This reduces the complexity of computing the event and avoids to know the Lyapunov function.

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International audienceEvent-triggered control is a resource-aware sampling strategy that updates the control value only when a certain condition is satis ed, which denotes event instants. Such a technique allows to reduce the control computational cost and communications. In this paper, a quaternion-based feedback is developed for event-triggered attitude stabilization of a quadrotor mini-helicopter. The feedback is derived from the universal formula for eventtriggered stabilization of general nonlinear systems a ne in the control. The proposed feedback ensures the asymptotic stability to the desired attitude. Real-time experiments are carried out in order to show the convergence of the quadrotor states to the desired attitude as well as the robustness with respect to external disturbances. Results show that the proposed control can reduce by 80 % the communications of the embedded system without sacri cing performance of the whole system. To the best of the authors' knowledge, this is the rst time that a nonlinear event-triggered controller is experimentally applied to the attitude stabilization of an unmanned aircraft system