Maria Domenica Di Benedetto

Università degli Studi dell'Aquila | Università dell'Aquila · Department of Information Engineering, Computer Science and Mathematics

Interconnected and autonomous vehicles are proven to be helpful in reducing traffic congestion and dangerous emissions while enhancing safety on our roads. In this context, the present paper introduces a human-inspired Adaptive Cruise Control dedicated to improving the passenger experience using Model Predictive Control and traffic macroscopic info...

In this chapter, LH-systems with full discrete state information are considered. We have shown in Chap. 9 that observability as defined in Chap. 6 can be characterized in terms of finite time convergence to zero of all the trajectories with infinite time duration of an appropriate LH-system associated with the given one. However, verifying this con...

In this chapter, we describe two automotive control applications of the hybrid-observer design methodology illustrated in the previous chapter. We first consider the problem of on-line identification of the actual engaged gear for a car. The relevance of this problem is related to engine control strategies achieving high performance and efficient e...

Hybrid systems’ observability involves both the discrete structure and the continuous dynamics of the system, but it is not a simple extension of the same concept established for discrete state systems and for standard dynamic systems, because of the interaction between discrete and continuous components. In this chapter, we define observability fo...

In this chapter, we refer to the discrete structure of the H-system to define and characterize observability, diagnosability, and predictability of a Finite State Machine (FSM). Observability corresponds to the reconstruction of the system’s discrete state, while diagnosability and predictability correspond to the possibility of determining the pas...

In this chapter, we refer to the discrete structure of the H-system to extend the diagnosability properties illustrated in Chap. 4. In particular, in addition to the delay required for the detection of a critical state, some additional parameters are introduced, which represent the precision of the delay estimation and the duration of a possible in...

The previous chapters were centered on the analysis of observability, diagnosability and predictability properties of a hybrid system, without explicitly addressing the observer design problem. In this section, we illustrate a methodology for the design of hybrid observers for current location observable LH-systems, and we show the role of the rate...

In this chapter, some properties of the Finite State Machine \(M=\left( Q,Q_{0},Y,h,E\right) \) defined in Eq. (2.5), which abstracts the dependence of the discrete dynamics of \(\mathcal {H}\) from its continuous evolution, are analyzed. In particular, we introduce the notions of Strongly connected components, Persistent states, and Traps. Then, s...

In this chapter, after extending to H-systems the diagnosability and predictability definitions already given for FSMs in Chap. 4, we propose two different approaches to check those properties. The first one applies to the subclass of LH-systems and is based on the Enriching Procedure, described in Sect. 8.2. This procedure encodes in the discrete...

The observability property as defined in Chap. 6 requires the exact discrete state reconstruction in finite time. In the first part of this chapter, we focus specifically on this particular aspect and define the class of current location observable H-systems, that is H-systems for which the current location, i.e. the current discrete state, can be...

In this chapter, we analyze the possibility of determining the current discrete state of an LH-system by using only the continuous output information. The identification of the discrete mode of a hybrid system corresponds to understanding which continuous dynamical system is evolving. The main role in the solution to this problem is played by the n...

In this chapter, H-systems are defined and their expressive power is discussed with respect to other formalisms, such as Impulsive Systems and Piecewise-Affine (PWA) systems. Some illustrative examples of H-systems are also presented.

In an H-system, both continuous outputs and discrete outputs are in general available. In this chapter, we focus on how continuous and discrete information can be combined to obtain an H-system having only purely discrete outputs. Such a system will be shown to be useful in giving conditions for the observability of the given H-system. Similarly, f...

This article exploits macroscopic information for the control of autonomous vehicles in platoon formation in case of external disturbances. The use of such information leads to smoother platooning. A mesoscopic controller is proposed, and disturbance string stability is proven through input-to-state stability concepts. Simulations prove the efficac...

The capability to compute a partition of a cluttered environment starting from the obstacles that lie in it enables the construction of a route connecting an initial point to a desired final one. In this paper, we revisit the convex lifting method for the computation of a suitable partition of the cluttered environment with the objective to propose...

Diabetes is a widespread disease characterized by chronic hyperglycemia so that diabetic individuals usually require the administration of exogenous insulin for survival. As a consequence, in the context of the so-called artificial pancreas, many glucose control methods have been presented in the last few years. In this work, we focus on type-2 dia...

In this paper we address data-driven control design with regular language specifications for plants described as abstract systems, i.e. as collections of input-state functions. The abstract system is assumed to be suffix and concatenation closed, causal, deterministic and time-invariant. The system is unknown, apart from a collected finite set of e...

We present a general framework for the control of a direct current (DC) microgrid with star topology (a common DC bus) consisting of renewable sources of energy, loads, and storage devices connected via step-up and step-down DC/DC converters. The control objective is guaranteeing voltage stability in the DC microgrid while delivering power to the l...

The paper investigates the possibility of using macroscopic information to improve control performance of a vehicular platoon composed of autonomous vehicles. A mesoscopic traffic modeling framework is proposed, and closed loop String Stability is achieved by exploiting Input-to-State Stability (ISS) for the analysis of the platoon. Examples of mes...

Reports on recent activities and events to CSS society members.

This paper deals with large-scale interconnected systems with general network topology, affected by external disturbances, and with the possibility to ensure the overall stability when some sufficient conditions are met by each agent with respect to its neighbors. We introduce the notion of scalable Mesh Stability (sMS), that requires the existence...

In this letter control design of nondeterministic finite state systems with reachability specifications is addressed. The class of controllers we use is rather general and combines feedforward and output feedback schemes. The proposed controller allows not only the state of the system to reach the desired target set but also the identification of w...

We investigate the possibility to use macroscopic information to improve control performance of a vehicular platoon composed of autonomous vehicles. A general mesoscopic traffic modeling is described, and a closed loop String Stability analysis is performed using Input-to-State Stability (ISS) results. Examples of mesoscopic control laws are provid...

In this paper, we introduce and characterize the notion of approximate predictability for the general class of pseudo-metric systems, which are a powerful modeling framework to deal with complex heterogeneous systems such as hybrid systems. Approximate predictability corresponds to the possibility of predicting the occurrence of specific states bel...

The use of macroscopic information to improve control performance of a vehicular platoon composed of autonomous vehicles is investigated. General mesoscopic control laws are provided, and a String Stability analysis is performed using Lyapunov functions and Input-to-State Stability (ISS)concepts. Simulations are implemented in order to validate the...

We present a novel solution to the attitude control problem of ground vehicles by means of the Active Front Steering (AFS) system. The classical feedback linearization method is often used to track a reference yaw dynamics while guaranteeing vehicle stability and handling performance, but it is difficult to apply because it relies on the exact know...

Data-driven control design for general systems with regular language specifications is addressed. We consider a discrete-time control system described as an abstract system i.e. as a collection of input-state functions. The abstract system is assumed to be suffix and concatenation closed, causal, deterministic and time-invariant. State variables ar...

Formal methods have been recently used as the basis of a systematic framework to address control design of continuous or hybrid systems with specifications expressed in a logic form. However, results available in the literature assume full information of the state, or of its quantization. This information may not be available in relevant applicatio...

Many process control problems with complex qualitative specifications cannot be addressed via conventional control design methods. Examples of such specifications include logic specifications expressed in the design of start-up, shut-down, changeover, and emergency shutdown operating procedures. In recent years, it has been shown in the control sys...

A power management controller for a DC MicroGrid containing renewable energy sources, storage elements and loads is presented. The controller ensures power balance and grid stability even when some devices are not controllable in terms of their power output, and environmental conditions and load vary in time. Power balance and desired voltage level...

There is a growing interest in Industry and Academia in large scale composite systems where a number of physical processes are interfaced with intelligent units that control them and govern their interactions. Examples are manufacturing plants, drone swarms, and autonomous connected cars. These systems belong to the category of Cyber-Physical Syste...

The transition probabilities of jumps between operational modes of discrete-time Markov(ian) jump linear systems (dtMJLSs) are generally considered to be time-invariant, certain, and often completely known in the majority of dedicated studies. Still, in most real cases the transition probability matrix (TPM) cannot be computed exactly and is time-v...

Cyber-physical systems are integrations of computation, networking, and physical processes. Due to the tight cyber-physical coupling and to the potentially disrupting consequences of failures, security here is one of the primary concerns. Our systematic mapping study sheds light on how security is actually addressed when dealing with cyber-physical...

In this paper we introduce and characterize the notion of approximate predictability for the general class of metric systems, which are a powerful modeling framework to deal with complex heterogeneous systems such as hybrid systems. Approximate predictability corresponds to the possibility of predicting the occurrence of specific states belonging t...

The characterization of the behavior that can be achieved by a plant when interconnected with a controller is a topic widely investigated in mathematical systems theory. In this regard, many results have been obtained for several classes of continuous systems, and also for discrete–event and hybrid systems. However, current literature is rather sca...

The aim of this paper is to synthesize a hybrid controller for pressure swing adsorption (PSA) processes. Since the process is described by a set of partial differential algebraic equations, first a local reduced-order model (LROM) for the process is developed and is formalized as a hybrid system. A hybrid controller is designed for purity control...

In this paper we investigate how to predict the future occurrence of specific discrete states of a finite state system on the basis of the observations. Predictability property is defined with respect to a subset of discrete states, called critical set, representing for example faulty states or, more generally, any subset of states which is of part...

Networked Control Systems (NCS) are distributed systems where plants, sensors, actuators and controllers communicate over shared networks. Non-ideal behaviors of the communication network include variable sampling/transmission intervals and communication delays, packet losses, communication constraints and quantization errors. NCS have been the obj...

Observability and diagnosability properties of a hybrid dynamical system are essential in characterizing the possibility of identifying the system’s hybrid state, and in particular the occurrence of some specific states that may correspond to a malfunctioning of the system due to a fault or an attack. Diagnosability has been extensively studied for...

In this paper, a wireless networked control system is made robust with respect to packet losses by exploiting routing redundancy. Multiple copies of sensing and actuation data are sent via different routing paths, associated to possibly different delays. Similar to linear network coding, such data are recombined as a weighted linear combination. A...

In this paper we investigate how to predict the future occurrence of specific discrete states of a finite state system on the basis of the observations. Predictability property is defined with respect to a subset of discrete states, called critical set, representing for example faulty states or, more generally, any subset of states which is of part...

In this paper we introduce and characterize the notion of approximate predictability for the general class of metric systems, which are a powerful modeling framework to deal with complex heterogeneous systems such as hybrid systems. Approximate predictability corresponds to the possibility of predicting the occurrence of specific states belonging t...

Motivated by safety-critical applications in cyber–physical systems, in this paper we study the notion of critical observability and design of observers for networks of Finite State Machines (FSMs). Critical observability corresponds to the possibility of detecting if the current state of an FSM is in a given region of interest, called set of criti...

A hybrid controller is proposed for Pressure Swing Adsorption (PSA) processes. Since the process is described by a set of Partial Differential Algebraic Equations (PDAE's), first a Local Reduced Order Model (LROM) for the process is developed and then it is formalized as a hybrid system. A controller is designed for purity control of the process in...

In this paper we propose a method towards purity control of Pressure Swing Adsorption (PSA) processes which is based on the use of hybrid systems formalism. Hybrid systems feature both continuous and discrete-event dynamics and hence are very suited to describe in detail PSA processes. Based on mechanistic model of the processes, a Local Reduced-Or...

The increasing complexity in nowadays engineered systems requires great attention to safety hazards and occurrence of faults, which must be readily detected to possibly restore nominal behavior of the system. The notion of diagnosability plays a key role in this regard, since it corresponds to the possibility of detecting within a finite delay if a...

In this paper we present Lyapunov characterizations of the global asymptotic stability, the input-to-state stability and the incremental input-to-state stability for discrete-time nonlinear systems with uncertain and time-varying time-delays.We provide necessary and sufficient conditions for the global asymptotic stability and for the input-to-stat...

The increasing complexity in nowadays engineered systems requires great attention to safety hazards and occurrence of faults, which must be readily detected to possibly restore nominal behavior of the system. The notion of diagnosability plays a key role in this regard, since it corresponds to the possibility of detecting within a finite delay if a...

DC MicroGrids are presently considered as the best solution for renewable energy diffusion since they represent the most effective way for interconnecting renewables and storages with modern loads such as electric vehicles. Hierarchical control composed by different levels is usually adopted and communication among the controllers is used to ensure...

Markov jump switched linear systems (MJSLSs) are switched linear systems, where a switching signal is governed by a Markov decision process. We consider a polytopic time-inhomogeneous setting, where the transition probabilities (between the operational modes of the system) associated to each discrete action are varying over time, with variations th...

Related to Networked Control Systems, the interaction between information theory and control theory is expected to be more and more important to improve the performance of control loops closed over wireless communication networks. In this work, we consider quantized state measurements relayed to a controller via a communication network adopting the...

In this work we derive necessary and sufficient conditions for robust mean square stability of discrete-time time-inhomogeneous Markov jump linear systems (MJLSs) affected by polytopic uncertainties on transition probabilities and bounded disturbances.

DC MicroGrids present an increasing interest as they represent an advantageous solution for interconnecting renewable energy sources, storage systems and loads as electric vehicles. A high-level management system able to calculate the optimal reference values for the local controllers of each of the DC MicroGrid interconnected devices is introduced...

In this paper we aim at rendering a wireless networked control system robust with respect to packet losses exploiting routing redundancy. More precisely, we send multiple copies of sensing and actuation data via different routing paths, associated to possibly different delays and packet loss probability, and assume that such data can be re-combined...

Switching systems are an important mathematical formalism when dealing with Cyber-Physical Systems (CPSs). In this paper we provide conditions for the exact reconstruction of the initial discrete state of a switching system, when only the continuous output is measurable, and the discrete output signal is not available. In particular, assuming that...

This paper deals with diagnosability of discrete-time nonlinear systems with unknown inputs and quantized outputs. We propose a novel notion of diagnosability that we term approximate diagnosability, corresponding to the possibility of detecting within a finite delay and within a given accuracy if a set of faulty states is reached or not. Addressin...

New connection constraints for the power network (Grid Codes) require more flexible and reliable systems, with robust solutions to cope with uncertainties and intermittence from renewable energy sources (renewables), such as photovoltaic arrays. The interconnection of such renewables with storage systems through a Direct Current (DC) MicroGrid can...

This paper addresses the problem of vehicle attitude control by means of active front steering and rear torque vectoring in the presence of saturating actuators. A novel approach of actuation balancing is proven to be the optimal way to keep the vehicle off saturation or, at least, to postpone the saturation occurrences as much as possible. To this...

In this paper we propose definitions of equivalence via stochastic bisimulation and of equivalence of stochastic external behavior for the class of discrete-time stochastic linear control systems with possibly degenerate normally distributed disturbances. The first notion is inspired by the notion of probabilistic bisimulation for probabilistic cha...

In this note, we propose symbolic models for networks of discrete-time nonlinear control systems. If each subsystem composing the network admits an incremental input-to-state stable Lyapunov function and if some small gain theorem-type conditions are satisfied, a network of symbolic models, each one associated with each subsystem composing the netw...

New connection constraints for the power network (Grid Codes) require more flexible and reliable systems, with robust solutions to cope with uncertainties and intermittence from renewable energy sources (renewables), such as photovoltaic arrays. A solution for interconnecting such renewables to the main grid is to use storage systems and a Direct C...

In this paper a mesoscopic hybrid model, i.e. a microscopic hybrid model that takes into account macroscopic parameters, is introduced for designing a human-inspired Adaptive Cruise Control. A control law is proposed with the design goal of replacing and imitating the behaviour of a human driver in a car-following situation where lane changes are p...

A Multi-hop Control Network (MCN) consists of a dynamical system where the communication between sensors, actuators and computational units is supported by a (wireless) multi-hop communication network and data flow is performed using scheduling and routing of sensing and actuation data. Secure stabilization of an MCN is a challenging open problem t...

In this paper, a general framework is proposed for the analysis and characterization of observabil- ity and diagnosability of ?nite state systems. Observability corresponds to the reconstruction of the system's discrete state, while diagnosability corresponds to the possibility of determining the past occurrence of some particular states, for examp...

New connection constraints for the power network (Grid Codes) require more flexible and reliable systems, with robust solutions to cope with uncertainties and intermittence from renewable energy sources (renewables), such as photovoltaic arrays. A solution for interconnecting such renewables to the main grid is to use storage systems and a Direct C...

Cyber-physical systems are integrations of computation, networking, and physical processes. Due to the tight cyber-physical coupling and to the potentially disrupting consequences of failures, security here is one of the primary concerns. Our systematic mapping study sheds some light on how security is actually addressed when dealing with cyber-phy...

Hybrid systems, i.e., heterogeneous systems that include discrete and continuous time subsystems, have been used to model applications in automotive such as engine, brake, and stability control, as well as air traffic control and manufacturing plant control. Because of their generality (they include as special cases continuous and discrete systems)...

Hybrid systems have many applications in automotive, such as engine, brake and stability control, air traffic control and manufacturing plant control. The most effective hybrid control algorithms are based on full state feedback. However, in most cases, only partial information about the internal state of the hybrid plant can be measured. Observabi...

In this paper we investigate the exploitation of redundancy when routing actuation data to a discrete-time LTI system connected to the controller via a wireless network affected by packet drops. We assume that actuation packets can be delivered from the controller to the actuator via multiple paths, each associated with a delay and a packet loss pr...

The increase of functionality offered by today’s control systems based on embedded systems requiresmore effort to verify the controlled system, as amalfunction can yield catastrophic results. These systems are usually hybrid systems, mixing continuous and discrete dynamics. When analyzing a hybrid system, the dimension of the state space is often s...

In this paper we investigate the exploitation of redundancy when routing actuation data to a discrete-time LTI system connected to the controller via a wireless network affected by packet drops. We assume that actuation packets can be delivered from the controller to the actuator via multiple paths, each associated with a delay and a packet loss pr...

In this paper a mesoscopic hybrid automaton is introduced in order to obtain a human-inspired based adaptive cruise control. The proposed control law fits the design target of replacing and imitating a human driver behaviour. A microscopic hybrid automaton model for longitudinal vehicle control based on human psycho-physical behavior is first prese...

A Multi-hop Control Network consists of a plant where the communication between sensors, actuators and computational units is supported by a (wireless) multi-hop communication network, and data flow is performed using scheduling and routing of sensing and actuation data. With the aim of rendering the system robust with respect to packet losses, we...

We consider a particular class of hybrid systems characterized by a finite state machine and a set of discrete-time linear dynamical systems, each corresponding to a state of the machine. The hybrid control problem addressed consists of maintaining the output of the systems in a given subset of the output space, independently of the state of the FS...

This paper is a first step towards a mathematical and simulative environment to formally model the effect of router/link failures on the dynamics of TCP and UDP packet flows belonging to different end-user services (i.e. http, ftp, mailing and video streaming) transiting through a Service Provider backbone network. Our model takes into account netw...

Symbolic models have recently spurred the interest of the research community because they offer a correct-by-design approach to the control of embedded and cyber-physical systems. In this paper we address construction of symbolic models for networks of discrete-time nonlinear control systems. The main result of the paper shows that under some small...

Time-delay systems are an important class of dynamical systems that provide a solid mathematical framework to deal with many application domains of interest. In this paper we focus on nonlinear control systems with unknown and time-varying delay signals and we propose one approach to the control design of such systems, which is based on the constru...

Networked Control Systems (NCS) are distributed control systems where the communication among plants, sensors, actuators and controllers occurs in a shared communication network. NCS have been the subject of intensive study in the last few years. Important results have been obtained, mainly on stability and stabilizability of these systems. While s...