Luis Felipe da Cruz Figueredo

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In this paper, a robust stability criterion is proposed for NCSs liable to model uncertainties and time-varying delays. The analysis concerns the establishment of a maximum allowable delay bound for continous time NCSs under parameter uncertainties. The new proposed criterion is based on the solution of a set of Linear Matrix Inequalities (LMIs). Numerical(More)
Despite the solid contribution of recent techniques for the analysis of networked controls systems (NCSs), the use of dynamic controllers has received little attention in the literature. Adapting these methods to consider dynamic controllers in the feedback loop is seldom trivial, however, neglecting this class of controllers restricts the universe of(More)
This paper addresses the H<sub>&#x221E;</sub> robust control problem for robot manipulators using unit dual quaternion representation, which allows an utter description of the end-effector transformation without decoupling rotational and translational dynamics. We propose three different H<sub>&#x221E;</sub> control criteria that ensure asymptotic(More)
This paper presents a new strategy for task space control in the cooperative manipulation framework. We extend the cooperative dual task-space (CDTS) - which uses dual quaternions to represent the bimanual manipulation-to explicitly regard self-motion dynamics that arise from redundant kinematics. In this sense, we propose a flexible task execution(More)
Network-induced delays and packet dropouts are relevant issues that can degrade networked control systems’ performance and may even lead to instability. This paper concerns the establishment of a stability criterion for networked control systems (NCSs) consisting of an LTI process and a dynamic feedback controller. Conditions for stability are provided in(More)
In this paper, stability criteria are proposed for linear systems liable to model uncertainties and with the delay and its derivative varying within intervals. The results are an improvement over previous ones due to the development of a new Lyapunov-Krasovskii functional (LKF). The analysis incorporates recent advances such as convex optimization technique(More)
This work addresses the task-space design problem of a linear-quadratic optimal tracking controller for robotic manipulators using the unit dual quaternion formalism. The efficiency, compactness, and lack of singularity of the representation render the unit dual quaternion a suitable framework for simultaneously describing the attitude and the position of(More)