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作者：Ouyang, Hupo; Lin, Yan
作者单位：Beihang University; Shandong University of Science & Technology
摘要：In this article, an adaptive fault-tolerant control (FTC) scheme is proposed for a class of uncertain nonlinear systems with actuator failures, in which a backup actuator is available. Different from existing FTC methods applying dynamic redundant actuators, a situation of deferred actuator replacement is firstly taken into account, i.e., the backup one cannot connect to plant right after failure detection. To recover the tracking error into prescribed performance within a specified time, an e...
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作者：Zanon, Mario; Gros, Sebastien
作者单位：IMT School for Advanced Studies Lucca; Norwegian University of Science & Technology (NTNU)
摘要：Reinforcement learning (RL) has recently impressed the world with stunning results in various applications. While the potential of RL is now well established, many critical aspects still need to be tackled, including safety and stability issues. These issues, while secondary for the RL community, are central to the control community that has been widely investigating them. Model predictive control (MPC) is one of the most successful control techniques because, among others, of its ability to p...
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作者：Doria-Cerezo, Arnau; Olm, Josep M.; Biel, Domingo; Fossas, Enric
作者单位：Universitat Politecnica de Catalunya; Universitat Politecnica de Catalunya; Universitat Politecnica de Catalunya; Universitat Politecnica de Catalunya
摘要：A number of physical systems allow a complex-valued representation. This article extends the theory of sliding modes to a class of nonlinear systems described by complex-valued variables. Hence, states, parameters, control actions, and sliding manifolds belong, in general, to the complex field. In this article, it is also shown that the proposed design in the complex-valued framework provides shorter reaching times to the sliding manifold than the standard sliding-mode design at equal initial ...
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作者：Wen, Min; Topcu, Ufuk
作者单位：University of Pennsylvania; Alphabet Inc.; Google Incorporated; University of Texas System; University of Texas Austin
摘要：We study a safe reinforcement learning problem, in which the constraints are defined as the expected cost over finite-length trajectories. We propose a constrained cross-entropy-based method to solve this problem. The key idea is to transform the original constrained optimization problem into an unconstrained one with a surrogate objective. The method explicitly tracks its performance with respect to constraint satisfaction and thus is well suited for safety-critical applications. We show that...
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作者：Xiao, Qiang; Zeng, Zhigang; Huang, Tingwen; Lewis, Frank L.
作者单位：Huazhong University of Science & Technology; Qatar Foundation (QF); Texas A&M University Qatar; University of Texas System; University of Texas Arlington
摘要：In this article, positivity and global exponential stability for a class of timescale-type differential-difference equations with bounded time-varying delay are considered. At first, a sufficient and necessary condition for the positivity of matrix-valued timescale-type exponential function is obtained. Based on this, an explicit criterion for the positivity of coupled timescale-type differential-difference equations with delays bounded above is acquired by timescale-type induction method. Bes...
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作者：Akhtar, Adeel; Waslander, Steven L.
作者单位：University of Toronto
摘要：In this article, we propose a novel family of Lie algebra valued functions F-R on special orthogonal group SO(3). Each function belonging to this family induces a novel controller that stabilizes a rigid body attitude. All controllers induced by the family F-R form a controller class C-R. This novel controller class C-R contains both local and almost-global asymptotically stable controllers, and this article presents geometric stability results of the whole controller class C-R.
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作者：Ghadiri-Modarres, Mohammadali; Mojiri, Mohsen
作者单位：Isfahan University of Technology
摘要：A suitable normalization technique is introduced to improve the robustness properties of the conventional perturbation-based extremum seeking (ES). Following practical stability analysis, an appropriate expression is found for the normalization signal in the proposed normalized ES. Application of the proposed scheme in the source localization with nonholonomic unicycle has an additional advantage of ensuring that forward and angular velocities of the unicycle have a priori known bounds.
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作者：Mi, Wen; Zheng, Wei Xing
作者单位：University of Electronic Science & Technology of China; Western Sydney University
摘要：In this article, we present two algorithms for identification of continuous-time linear time-invariant systems in frequency domain. These algorithms are constructed in terms of continuous rational orthogonal basis functions. First, a two-stage algorithm is developed through one-by-one selection of poles for the basis functions, and such consecutive selection is easy to realize. Next, a direct algorithm is proposed to select poles for the rational orthogonal basis functions. Different poles res...
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作者：Giuseppi, Alessandro; Pietrabissa, Antonio
作者单位：Sapienza University Rome
摘要：This article presents a multicommodity, discrete-time, distributed, and noncooperative routing algorithm, which is proved to converge to an equilibrium in the presence of heterogeneous, unknown, time-varying but bounded delays. Under mild assumptions on the latency functions, which describe the cost associated with the network paths, two algorithms are proposed: The former assumes that each commodity relies only on measurements of the latencies associated with its own paths; the latter assumes...
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作者：Ma, Hong-Jun; Yang, Guang-Hong; Chen, Tongwen
作者单位：Northeastern University; University of Alberta
摘要：This article studies an optimal dynamic formation problem for heterogeneous affine nonlinear systems. The nonidenticality in agents and the requirement for dynamic spatial reconfiguration make it a challenging task to coordinate different types of agents to maintain an optimized formation shape. In an architecture of event-triggered decision and control, this article investigates how to fulfill dynamic formation by distributively optimizing a team cost function. The basic idea is to design a d...
