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This paper presents a nonlinear robust control strategy to solve the path tracking problem for a quadrotor unmanned aerial vehicle. The helicopter motion equations is obtained by the LagrangeEuler formalism. The control structure is performed through a nonlinear H ∞ controller to stabilize the rotational movements and a control law based on backstepping approach to track the reference trajectory. Finally, simulations results in presence of aerodynamic moments disturbances and parametric uncertainty is carried out to corroborate the effectiveness and the robustness of the strategy proposed.

This paper presents new methods for set-valued state estimation of nonlinear discrete-time systems with unknown-but-bounded uncertainties. A single time step involves propagating an enclosure of the system states through the nonlinear dynamics (prediction), and then enclosing the intersection of this set with a bounded-error measurement (update). When these enclosures are represented by simple sets such as intervals, ellipsoids, parallelotopes, and zonotopes, certain set operations can be very conservative. Yet, using general convex polytopes is much more computationally demanding. To address this, this paper presents two new methods, a mean value extension and a first-order Taylor extension, for efficiently propagating constrained zonotopes through nonlinear mappings. These extend existing methods for zonotopes in a consistent way. Examples show that these extensions yield tighter prediction enclosures than zonotopic estimation methods, while largely retaining the computational benefits of zonotopes. Moreover, they enable tighter update enclosures because constrained zonotopes can represent intersections much more accurately than zonotopes. AbstractThis supplement details the derivation of the computational complexities of basic operations on zonotopes and constrained zonotopes, and the set-valued state estimators presented in the main paper.

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This paper presents a nonlinear robust control strategy to solve the path tracking problem for a quadrotor unmanned aerial vehicle. The main objective is to design controllers that provide certain required performances during the quadrotor flight, such as null tracking error and robustness in the presence of sustained external disturbances affecting the six degrees of freedom, parametric uncertainties, and unmodeled dynamics. The control structure is performed through a nonlinear H ∞ controller to stabilize the rotational movements and a control law based on the backstepping approach with integral action to track the reference trajectory. Simulation results are carried out to corroborate the effectiveness and the robustness of the proposed strategy.

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