55 research outputs found
Model predictive control with dynamic move blocking
Model Predictive Control (MPC) has proven to be a powerful tool for the
control of systems with constraints. Nonetheless, in many applications, a major
challenge arises, that is finding the optimal solution within a single sampling
instant to apply a receding-horizon policy. In such cases, many suboptimal
solutions have been proposed, among which the possibility of "blocking" some
moves a-priori. In this paper, we propose a dynamic approach to move blocking,
to exploit the solution already available at the previous iteration, and we
show not only that such an approach preserves asymptotic stability, but also
that the decrease of performance with respect to the ideal solution can be
theoretically bounded.Comment: 7 page
Uncertainty-aware data-driven predictive control in a stochastic setting
Data-Driven Predictive Control (DDPC) has been recently proposed as an
effective alternative to traditional Model Predictive Control (MPC), in that
the same constrained optimization problem can be addressed without the need to
explicitly identify a full model of the plant. However, DDPC is built upon
input/output trajectories. Therefore, the finite sample effect of stochastic
data, due to, e.g., measurement noise, may have a detrimental impact on
closed-loop performance. Exploiting a formal statistical analysis of the
prediction error, in this paper we propose the first systematic approach to
deal with uncertainty due to finite sample effects. To this end, we introduce
two regularization strategies for which, differently from existing
regularization-based DDPC techniques, we propose a tuning rationale allowing us
to select the regularization hyper-parameters before closing the loop and
without additional experiments. Simulation results confirm the potential of the
proposed strategy when closing the loop.Comment: 6 pages, 1 figure, this work has been submitted and accepted for
publication at the IFAC World Congress 2023, Yokohama, Japa
Direct data-driven design of LPV controllers with soft performance specifications
If only experimental measurements are available, direct data-driven control design becomes an appealing approach, as control performance is directly optimized based on the collected samples. The direct synthesis of a feedback controller from input-output data typically requires the blind choice of a reference model, that dictates the desired closed-loop behavior. In this paper, we propose a data-driven design scheme for linear parameter-varying (LPV) systems to account for soft performance specifications. Within this framework, the reference model is treated as an additional hyper-parameter to be learned from data, while the user is asked to provide only indicative performance constraints. The effectiveness of the proposed approach is demonstrated on a benchmark simulation case study, showing the improvement achieved by allowing for a flexible reference model.</p
Direct Data-Driven Model-Reference Control with Lyapunov Stability Guarantees
In this work, we introduce a novel data-driven model-reference control design
approach for unknown linear systems with fully measurable state. The proposed
control action is composed by a static feedback term and a reference tracking
block, which are shaped from data to reproduce the desired behavior in
closed-loop. By focusing on the case where the reference model and the plant
share the same order, we propose an optimal design procedure with Lyapunov
stability guarantees, tailored to handle state measurements with additive
noise. Two simulation examples are finally illustrated to show the potential of
the proposed strategy as compared to the state of the art approaches.Comment: 8 pages, 10 figures, Preprint submitted to the 60th IEEE Conference
on Decision and Control (CDC) 202
Direct data-driven model-reference control with Lyapunov stability guarantees
In this work, we introduce a novel data-driven model-reference control design
approach for unknown linear systems with fully measurable state. The proposed
control action is composed by a static feedback term and a reference tracking
block, which are shaped from data to reproduce the desired behavior in
closed-loop. By focusing on the case where the reference model and the plant
share the same order, we propose an optimal design procedure with Lyapunov
stability guarantees, tailored to handle state measurements with additive
noise. Two simulation examples are finally illustrated to show the potential of
the proposed strategy as compared to the state of the art approaches.Comment: 8 pages, 10 figures, Preprint submitted to the 60th IEEE Conference
on Decision and Control (CDC) 202
Hydrogen sulfide releasing capacity of natural isothiocyanates: is it a reliable explanation for the multiple biological effects of brassicaceae?
Hydrogen sulfide is an endogenous pleiotropic gasotransmitter, which mediates important physiological effects in the human body. Accordingly, an impaired production of endogenous hydrogen sulfide contributes to the pathogenesis of important disorders. To date, exogenous compounds, acting as hydrogen sulfide-releasing agents, are viewed as promising pharmacotherapeutic agents. In a recent report, the hydrogen sulfide-releasing properties of some synthetic aryl isothiocyanate derivatives have been reported, indicating that the isothiocyanate function can be viewed as a suitable slow hydrogen sulfide-releasing moiety, endowed with the pharmacological potential typical of this gasotransmitter. Many isothiocyanate derivatives (deriving from a myrosinase-mediated transformation of glucosinolates) are well-known secondary metabolites of plants belonging to the family Brassicaceae, a large botanical family comprising many edible species. The phytotherapeutic and nutraceutic usefulness of Brassicaceae in the prevention of important human diseases, such as cancer, neurodegenerative processes and cardiovascular diseases has been widely discussed in the scientific literature. Although these effects have been largely attributed to isothiocyanates, the exact mechanism of action is still unknown. In this experimental work, we aimed to investigate the possible hydrogen sulfide-releasing capacity of some important natural isothiocyanates, studying it in vitro by amperometric detection. Some of the tested natural isothiocyanates exhibited significant hydrogen sulfide release, leading us to hypothesize that hydrogen sulfide may be, at least in part, a relevant player accounting for several biological effects of Brassicaceae
Different patterns of H2S/NO activity and cross-talk in the control of the coronary vascular bed under normotensive or hypertensive conditions
Hydrogen sulfide (H2S) and nitric oxide (NO) play pivotal roles in the cardiovascular system. Conflicting results have been reported about their cross-talk. This study investigated their interplays in coronary bed of normotensive (NTRs) and spontaneously hypertensive rats (SHRs). The effects of H2S- (NaHS) and NO-donors (sodium nitroprusside, SNP) on coronary flow (CF) were measured in Langendorff-perfused hearts of NTRs and SHRs, in the absence or in the presence of propargylglycine (PAG, inhibitor of H2S biosynthesis), L-NAME (inhibitor of NO biosynthesis), ODQ (inhibitor of guanylate cyclase), L-Cysteine (substrate for H2S biosynthesis) or L-Arginine (substrate for NO biosynthesis). In NTRs, NaHS and SNP increased CF; their effects were particularly evident in Angiotensin II (AngII)-contracted coronary arteries. The dilatory effects of NaHS were abolished by L-NAME and ODQ; conversely, PAG abolished the effects of SNP. In SHRs, high levels of myocardial ROS production were observed. NaHS and SNP did not reduce the oxidative stress, but produced clear increases of the basal CF. In contrast, in AngII-contracted coronary arteries of SHRs, significant hyporeactivity to NaHS and SNP was observed. In SHRs, the vasodilatory effects of NaHS were only modestly affected by L-NAME and ODQ; PAG poorly influenced the effects of SNP. Then, in NTRs, the vascular actions of H2S required NO and vice versa. By contrast, in SHRs, the H2S-induced actions scarcely depend on NO release; as well, the NO effects are largely H2S-independent. These results represent the first step for understanding pathophysiological mechanisms of NO/H2S interplays under both normotensive and hypertensive conditions
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