This paper reviews the vast literature on static output feedback design for linear time-invariant systems including classical results and recent developments. In particular, we focus on static output feedback synthesis with performance specifications, structured static output feedback, and robustness. The paper provides a comprehensive review on existing design approaches including iterative linear matrix inequalities heuristics, linear matrix inequalities with rank constraints, methods with decoupled Lyapunov matrices, and non-Lyapunov-based approaches. We describe the main difficulties of dealing with static output feedback design and summarize the main features, advantages, and limitations of existing design methods.

Abstract-The purpose of this paper is to explore the applicability of linear time-invariant (LTI) dynamical systems with polytopic uncertainty for modeling and control of islanded DC microgrids under plug-and-play (PnP) functionality of distributed generations (DGs). We develop a robust decentralized voltage control framework to ensure robust stability and reliable operation for islanded DC microgrids. The problem of voltage control of islanded DC microrgids with PnP operation of DGs is formulated as a convex optimization problem with structural constraints on some decision variables. The proposed control scheme offers several advantages including decentralized voltage control with no communication link, transient stability/performance, plug-and-play capability, scalability of design, applicability to microgrids with general topology, and robustness to microgrid uncertainties. The effectiveness of the proposed control approach is evaluated through simulation studies carried out in MATLAB/SimPowerSystems Toolbox.

Optimal anticipatory control as a theory of motor preparation: A thalamo-cortical circuit model Highlights d Motor preparation is formalized as optimal control of M1 population dynamics d Preparatory activity can vary in a large subspace without causing future motor errors d A thalamo-cortical loop implements the optimal feedback control (OFC) solution d OFC explains fast preparation and key features of monkey M1 activity during reaching

Abstract-This paper proposes a decentralized control strategy for the voltage regulation of islanded inverter-interfaced microgrids. We show that an inverter-interfaced microgrid under plugand-play (PnP) functionality of distributed generations (DGs) can be cast as a linear time-invariant (LTI) system subject to polytopic-type uncertainty. Then, by virtue of this novel description and use of the results from theory of robust control, the microgrid control system guarantees stability and a desired performance even in the case of PnP operation of DGs. The robust controller is a solution of a convex optimization problem. The main properties of the proposed controller are that 1) it is fully decentralized and local controllers of DGs use only local measurements, 2) the controller guarantees the stability of the overall system, 3) the controller allows plug-and-play functionality of DGs in microgrids, 4) the controller is robust against microgrid topology change. Various case studies, based on timedomain simulations in MATLAB/SimPowerSystems Toolbox, are carried out to evaluate the performance of the proposed control strategy in terms of voltage tracking, microgrid topology change, plug-and-play capability features, and load changes.

Across a range of motor and cognitive tasks, cortical activity can be accurately described by low-dimensional dynamics unfolding from specific initial conditions on every trial. These "preparatory states" largely determine the subsequent evolution of both neural activity and behaviour, and their importance raises questions regarding how they are -or ought to be -set. Here, we formulate motor preparation as optimal prospective control of future movements. The solution is a form of internal control of cortical circuit dynamics, which can be implemented as a thalamo-cortical loop gated by the basal ganglia. Critically, optimal control predicts selective quenching of variability in components of preparatory population activity that have future motor consequences, but not in others. This is consistent with recent perturbation experiments performed in mice, and with our novel analysis of monkey motor cortex activity during reaching. Together, these results suggest optimal anticipatory control of movement.Fast ballistic movements (e.g. throwing) require spa-1 lamocortical loop during motor preparation, with tha-62 lamic afferents providing the desired optimal control in-63 puts. This is consistent with the causal role of thalamus 64 in the preparation of directed licking in mice (Guo et al., 65 2017). Moreover, we posit that the basal ganglia oper-66 ate an on/off switch on the thalamocortical loop (Jin 67 and Costa, 2010; Cui et al., 2013; Halassa and Acsády, 68 2016; Logiaco et al., 2019), thereby flexibly controlling 69 the timing of both movement planning and initiation.70We further analyze the model, and formulate predic-71 tions which we have successfully tested in data. At the 72 most abstract level, our core prediction is that the "op-73 timal subspace" is likely high dimensional, with many 74 different initial conditions giving rise to the same cor-75 rect movement. This has an important consequence for 76 preparatory control: at the population level, only a few 77 components of preparatory activity impact future mo-78 tor outputs, and it is these components only that need 79 active controlling. In contrast, one expects substantial 80 pre-movement variability in other, inconsequential com-81 ponents. Concretely, we predict that following a pertur-82 bation, preparatory activity should recover only in state 83 space directions that matter for subsequent movement, 84 but not (necessarily) in others. We find that this pre-85 diction agrees with the effects of optogenetic perturba-86 tions reported by Svoboda and colleagues, in a directed 87 licking task in mice (Li et al., 2016). Furthermore, the 88 existence of a preparatory nullspace predicts selective 89 variability quenching at preparation onset: trial-by-trial 90 variability should drop predominantly in components 91 that have motor consequences. We perform novel analy-92 ses of monkey M1 and dorsal premotor cortex (PMd) ac-93 tivity recorded during reaching, and find that the struc-94 ture of variability quenching supports our main predic-95 tion. Finally...

This letter addresses the problem of voltage regulation and balanced current sharing in a parallel connection of heterogeneous DC-DC converters sharing a common ZIP (constant impedance, constant current, and constant power) load. To this end, a distributed dynamic control approach is developed. The proposed control approach does not rely on the load profile and the number of active converters. The paper describes theoretical aspects in rigorous Lyapunov-based stability analysis, loadindependent characteristic, scalability, and plug-and-play feature of the control design, and verifies the performance of the proposed control mechanism via simulation case studies in MATLAB/Simscape Electrical environment.

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This paper focuses on the problem of voltage control of islanded inverterinterfaced microgrids consisting of several distributed generation (DG) units with parallel structure. The main objectives are to (i) design a decentralized/distributed voltage controller with minimum information exchange between DG units and their local controllers (ii) design a fixed-/low-order dynamic output feedback controller which ensures stability as well as desired performance of the microgrid system in spite of load parameter uncertainties. To this end, the problem is formulated as an optimization problem which is the minimization of the cardinality of a pattern matrix subject to an H ∞ performance constraint. Since the problem is intrinsically non-convex, a convex design procedure for the controller synthesis is proposed in this paper. The effectiveness of the proposed controller is evaluated through simulation studies and Hardware-In-the-Loop (HIL) verifications. The simulation and experimental results demonstrate that the effectiveness of the proposed control strategy.