Papers by Francesco Tedesco
Proceedings of the 19th IFAC World Congress, 2014
This paper evaluates the application of command governor (CG) strategy for the operational contro... more This paper evaluates the application of command governor (CG) strategy for the operational control of drinking water networks (DWN) given their large-scale and complex nature, the permanent and relevant effect of the disturbances (water demands) and their marginal stability feature. Moreover, the performance improvement offered by CG is compared with the application of model predictive control for the same management purposes and in the same context. The paper also discusses the effectiveness of both strategies and highlights the advantages of each approach. The Barcelona DWN is considered as case study for the undertaken assessment analysis.
Vibration, 2020
Regenerative suspension systems, unlike traditional passive, semi-active or active setups, are ab... more Regenerative suspension systems, unlike traditional passive, semi-active or active setups, are able to convert the traditionally wasted kinetic energy into electricity. This paper discusses flexible multi-objective control design strategies based on LMI formulations to suitably trade-off between the usual road handling and ride comfort performance and the amount of energy to be harvested. An electromechanical regenerative vehicle suspension system is considered where the shock absorber of each wheel is replaced by a linear electrical motor which is actively governed. It is shown by simulations that multivariable centralized control laws designed on the basis of a full-car model of the suspension system are able to achieve larger amount of harvested energy under identical ride comfort prescriptions with respect to scalar decentralized control strategies, designed on the basis of a single quarter-car model and implemented independently on each wheel in a decentralized way. Improvement...
Distributed command governor strategies for multi-agent dynamical systems
Dottorato di Ricerca in Ingegneria dei Sistemi e Informatica XXIV Ciclo, a.a. 2011
Smart Cities, 2020
This paper reports the results of a recently concluded R&D project, SCALS (Smart Cities Adaptive ... more This paper reports the results of a recently concluded R&D project, SCALS (Smart Cities Adaptive Lighting System), which aimed at the development of all hardware/software components of an adaptive urban smart lighting architecture allowing municipalities to manage and control public street lighting lamps. The system is capable to autonomously adjust street lamps’ brightness on the basis of the presence of vehicles (busses/trucks, cars, motorcycles and bikes) and/or pedestrians in specific areas or segments of the streets/roads of interest to reduce the energy consumption. The main contribution of this work is to design a low cost smart lighting system and, at same time, to define an IoT infrastructure where each lighting pole is an element of a network that can increase their amplitude. More generally, the proposed smart infrastructure can be viewed as the basis of a wider technological architecture aimed at offering value-added services for sustainable cities. The smart architectur...
International Journal of Mathematical Models and Methods in Applied Sciences
Mathematical and computer tools of discrete dynamic modeling and analysis of complex systems in c... more Mathematical and computer tools of discrete dynamic modeling and analysis of complex systems in control loop
International Journal of Control, 2018
This paper proposes two fault-tolerant sensor reconciliation design methods for over-sensed plant... more This paper proposes two fault-tolerant sensor reconciliation design methods for over-sensed plants (see Fig. 1). The aim of the reconciliator is to detect, at each time instant, the presence of faults on the existing physical sensors y and hide the corrupted measurements in the generation of the virtual output z (with dim y ≥ dim z), which one would like to be generated in a reliable way in spite of fault occurrences and hence trustfully usable for control purposes. If the reconciliation scheme were effective, it would provide a reliable output z for feedback control and would exclude the need to reconfigure the nominal control law in case of faults. The sensor faults here considered are limited to variations of both sensor gain and offset values. The proposed approach envisages the use of an Unknown Input Observers (UIO) coupled with an "ad-hoc" parameters estimator used to estimate on-line the sensor effectiveness matrix at each time instant. In the paper, two design methodologies are described, based one on the Linear Parameter Varying (LPV) polytopic formulation and the other on the Linear Fractional Transformation (LFT) paradigm. All main properties of the sensor reconciliation schemes are investigated and rigorously proved. A final simulation example is included where both the LPV and LFT schemes are compared.
International Journal of Robust and Nonlinear Control, 2018
In this paper, a distributed command governor (CG) strategy is introduced that, by the use of gra... more In this paper, a distributed command governor (CG) strategy is introduced that, by the use of graph colorability theory, improves the scalability property and the performance of recently introduced distributed noncooperative sequential CG strategies. The latter are characterized by the fact that only 1 agent at a decision time is allowed to update its command, whereas all the others keep applying their previously computed commands. The scalability of these early CG distributed schemes and their performance are limited because the structure of the constraints is not taken into account in their implementation. Here, by exploiting the idea that agents that are not directly coupled by the constraints can simultaneously update their control actions, the agents in the network are grouped into particular subsets (turns). At each time instant, on the basis of a round-robin policy, all agents belonging to a turn are allowed to update simultaneously their commands, whereas agents in other turns keep applying their previous commands. Then, a turn-based distributed CG strategy is proposed and its main properties are analyzed. Graph colorability theory is used to determine the minimal number of turns and to distribute each agent in at least a turn. A novel graph colorability problem that allows one to maximize the frequency at which agents can update their commands is proposed and discussed. A final example is presented to illustrate the effectiveness of the proposed strategy.
International Journal of Robust and Nonlinear Control, 2017
In this paper, a switched control architecture for constrained control systems is presented. The ... more In this paper, a switched control architecture for constrained control systems is presented. The strategy is based on command governor ideas that are here specialized to 'optimally' schedule switching events on the plant dynamics for improving control performance at the expense of low computational burdens. The significance of the method mainly lies in its capability to avoid constraints violation and loss of stability regardless of any configuration change occurrence in the plant/constraint structure. To this end, the concept of model transition dwell time is used within the proposed control framework to formally define the minimum time necessary to enable a switching event under guaranteed conditions on the overall stability and constraint fulfilment. Simulation results on a simple linear system and on a Cessna 182 aircraft model show the effectiveness of the proposed strategy.
IEEE Transactions on Systems, Man, and Cybernetics: Systems, 2016
This paper evaluates the applicability of Command Governor (CG) strategies to the optimal managem... more This paper evaluates the applicability of Command Governor (CG) strategies to the optimal management of Drinking Water Supply Systems (DWSS) in both centralized and distributed ways. It will be shown that CG approaches provide an adequate framework for addressing the management of these large-scale interconnected systems in the presence of periodically time-varying disturbances (water demands) that can be anticipated by using time-series forecasting approaches. The proposed centralized and distributed CG schemes are presented, discussed and compared when applied to the management of DWSS considering the same set of operational goals in all cases. The paper illustrates the effectiveness of all strategies using the Barcelona DWSS as a case study and highlighting the advantages of each approach.
International Journal of Control, 2017
A significant amount of energy induced by road unevenness and vehicle roll and pitch motions is u... more A significant amount of energy induced by road unevenness and vehicle roll and pitch motions is usually dissipated by conventional shock absorbers. In this paper, a novel active multiobjective H∞ control design methodology is proposed which explicitly includes, besides the usual control objectives on ride comfort, road handling and suspension stroke, the amount of energy to be harvested as an additional, though conflicting, control objective and allows the designer to directly trade-off among them depending on the application. An electromechanical regenerative suspension system is considered where the viscous damper is replaced by a linear electrical motor which is actively governed. It is shown that the proposed control law is able to achieve remarkable improvements on the amount of the harvested energy with respect to passive or semi-active control strategies while maintaining the other objectives at acceptable levels. Simulative studies undertaken via CarSim are also reported that confirm the potentiality and flexibility of the proposed control design strategy.
A parallel distributed supervision strategy for multi-agent networked systems
Systems & Control Letters, 2016
Abstract This paper introduces a novel parallel distributed supervision strategy for interconnect... more Abstract This paper introduces a novel parallel distributed supervision strategy for interconnected linear systems subject to pointwise-in-time set-membership coordination constraints. The scheme is based on the Feed Forward Command Governor paradigm. It is assumed that the systems are locally regulated, possibly dynamically coupled, and connected via data links. The supervisor is in charge of enforcing coordination constraints by modifying, whenever necessary, the nominal reference signals so that the global coordination goal is achieved. The proposed method extends in a substantial way the sequential Distributed Command Governor previously developed by the authors by allowing each agent to modify its local reference in parallel with the others. The main idea consists in bounding each subsystem with a set of local artificial constraints able to ensure global constraints satisfaction. These virtual constraints are dynamically generated in a distributed way on the basis of the common information available to all agents. The proposed strategy is described and its properties analyzed. The performance of the obtained scheme is compared with previous solutions in the final example.
Unbiased Estimation of Sinusoidal Signal Parameters via Discrete-Time Frequency-Locked-Loop Filters
IEEE Transactions on Automatic Control, 2017
A novel class of discrete-time frequency-locked-loop nonlinear (FLL) filters is introduced and th... more A novel class of discrete-time frequency-locked-loop nonlinear (FLL) filters is introduced and their relevance for the on-line estimation of the parameters of a possibly time-varying sinusoidal signal is discussed. Continuous-time nonlinear FLL filters have been proposed in the literature because of their circuital simplicity and ability to provide unbiased estimates of the instantaneous frequency, phase and amplitude of a time-varying sinusoidal signal simultaneously. It is shown in this note that standard discretization techniques may fail to generate discrete-time FLL filters exhibiting the same good properties of the continuous-time domain. In particular, biased frequency estimates are usually produced by these discrete-time filters. In this note, such a drawback is overcome because the proposed discrete-time FLL filters are proved to enjoy semi-globally exponential stability and their estimates are unbiased. A final example is presented for assessment purposes where also comparisons with other discrete-time filters, among which some synthesized by means of standard discretization techniques, are provided.
Distributed Supervisory Strategies for Multi-agent Networked Systems
Complex Systems, 2016
Novel distributed supervisory strategies for multi-agent linear systems connected via data networ... more Novel distributed supervisory strategies for multi-agent linear systems connected via data networks and subject to coordination constraints are presented in this paper. Such a coordination-by-constraint paradigm is based on the online management of the prescribed set points and it is characterized by a set of spatially distributed dynamic systems, connected via communication channels, with possibly dynamical coupling amongst them which need to be supervised and coordinated in order to accomplish their overall objective. Two distributed strategies will be fully described and analysed. First, a “sequential” distributed strategy will be presented where only one agent per decision time is allowed to manipulate its own reference signal. Such a strategy will be instrumental to introduce a more effective “parallel” distributed strategy, in which all agents are allowed, under certain conditions, to modify their own reference signals simultaneously. Finally, some cases of study will be presented to show the effectiveness of the proposed methods.
IFAC-PapersOnLine, 2015
Economic Model Predictive Control is a technique for optimization of economic revenues arising fr... more Economic Model Predictive Control is a technique for optimization of economic revenues arising from controllod dynamical processes that has estabilished itself as a variant of standard Tracking Model Predictive Control. It departs from the latter in that arbitrary cost functions are allowed in the formulation of the stage cost. This paper takes a further step in expanding the applicability of Economic Model Predictive Control by illustrating how the paradigm can be adapted in order to accomodate time-varying or parameter-varying costs.
Economic Model Predictive Control-Based Strategies for Cost-Effective Supervision of Community Microgrids Considering Battery Lifetime
IEEE Journal of Emerging and Selected Topics in Power Electronics, 2015
Community-based microgrid (C-μGrid) systems are gaining increasing importance nowadays because of... more Community-based microgrid (C-μGrid) systems are gaining increasing importance nowadays because of the lack of μGrid public investment and management policies. Technoeconomic analysis shows that C-μGrid based on a cluster of microgenerators could be an effective solution when individual systems are not feasible. In this paper, the controlling capability of the central controller of the C-μGrid is improved through an economic model predictive control (EMPC) approach operating at the pricing level that can fulfill the goal of the operational control of the cluster. With a central controller, it is capable of satisfying the demand at prosumer (active energy producer and simultaneous consumer) sides and, at the same time, optimizing the various μGrid contrasting constraints. Emphasis here has been given to the operational constraints related to the battery lifetime, so that the maintenance and replacement costs would be reduced. A comparative analysis has been carried out between the performance of two systems, one based on an IF-THEN-ELSE heuristic supervision logic (S-LOGIC) and the other based on the proposed EMPC strategy. The analysis has been undertaken in a location in Dublin, Ireland, on the basis of available measured data. Simulation shows the effectiveness of implementing the EMPC approach to optimally manage the system.
A Steady-State Command Governor Strategy for Constrained Linear Systems
On average performance of Economic Model Predictive Control with time-varying cost and terminal constraints
2015 American Control Conference (ACC), 2015
This note extends from a theoretical perspective recent results in Economic Model Predictive Cont... more This note extends from a theoretical perspective recent results in Economic Model Predictive Control to the case of time-varying cost functionals and terminal constraints. Formal conditions are provided in order to achieve average performance bounds of the closed-loop system under suitable technical assumptions guaranteeing existence of an asymptotic average stage cost (for frozen control and state variables).
A dwell-time based Command Governor approach for constrained switched systems
2015 American Control Conference (ACC), 2015
In this paper a switched control architecture for constrained control systems is presented. The s... more In this paper a switched control architecture for constrained control systems is presented. The strategy is based on Command Governor (CG) ideas that are here specialized in order to jointly take into account switching events on the plant dynamics and time-varying constraints. The significance of the method relies in its capability to avoid constraint violation and loss of stability regardless of any configuration change in the plant/constraint structure by commuting the system configuration (model plant+CG) with a more adequate one. To this end the concept of model transition dwell time is used within the proposed control framework to formally define the minimum time necessary to enable a switching event under guaranteed conditions on the overall stability and constraint fulfillment.
A networked-based receding horizon scheme for constrained LPV systems
European Journal of Control, 2015
Abstract This paper deals with control problems for networked constrained polytopic Linear Parame... more Abstract This paper deals with control problems for networked constrained polytopic Linear Parameter Varying (LPV) systems. A novel LPV customization of a recent Receding Horizon robust Control (RHC) scheme developed for polytopic uncertainty systems is here proposed for the case where command inputs and state measurement are subject to time-varying delays. By taking advantage of the flexibility of the LPV structure, families of precomputed one-step controllable sets are off-line computed which result less conservative with respect to their robust counterparts. Finally, simulation results involving the constrained tracking problem of an unicycle-type mobile robot are reported to show the effectiveness and the benefits of the proposed control scheme.
Distributed Steady-State Command Governor Strategies for Interconnected Linear Systems
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Papers by Francesco Tedesco