Born in Ferrara in 1956, Riccardo Marino, received his degree in Nuclear engineering "cum laude" in July 1979 and the Master in Systems Engineering in 1981 from the University of Rome "La Sapienza". ...In 1982 he obtained the title of Doctor of Science in System Science and Mathematics from Washington University in St. Louis, Missouri, U.S.A. Since 1984 he has been with the Department of Electronic Engineering at the University of Rome "Tor Vergata" where he is Professor of Systems Theory (he was a researcher from 1984 to 1987 and Associate Professor from 1987 to 1990). He taught the course on Systems Theory from 1987 to 1999, the course on Dynamical Systems from 2000 to 2005. He currently teaches from 2000 the course on Nonlinear Systems. Professor Marino has visited the following institutions collaborating on joint research programs: University of Illinois at Urbana-Champaign, USA, in 1985/86, in 1989 and in 1990, Twente University in Enschede, The Netherlands, in 1986, Polytechnik of Kiev, Ukraine, in 1988, University of California at Santa Barbara, USA in 1992, Ecole des Mines de Paris, Fontainebleau, in 1999, Sophia University, Tokyo, in 2002 and in 2007. He is co-author of the book Nonlinear Control Design: Geometric, Adaptive and Robust, Prentice Hall, Hemel Hempstead, 1995, of more than 70 journal papers and more than 100 communications in international congresses. His scientific interests and contributions are mainly on the design of estimation and control algorithms and their applications to robots, electric machines, and vehicles. Professor Marino was the coordinator of the Doctoral Program in Sensor and Learning Systems Engineering at the University of Rome Tor Vergata from 1999 to 2007. He was associate editor of several scientific journals, member of the Directing Board of the European Control Association and director of several research projects financed by the Italian Ministry of University. Patrizio Tomei was born in Rome, Italy, on June 21, 1954. He received the "dottore" degree in Electronic Engineering in 1980 and the "dottore di ricerca" degree in 1987, both from the University of Rome "La Sapienza". He is currently Professor of Adaptive Systems at the University of Rome "Tor Vergata". He is co-author (with R. Marino) of the book Nonlinear Control Design (Prentice Hall, 1995). His research interests are in adaptive control, nonlinear control, robotics, and control of electrical machines. Cristiano Maria Verrelli was born in Italy on September 12, 1977. He received the Ph.D. in Systems Engineering from the University of Rome "Tor Vergata" in 2005. He has been visiting scholar at Laboratoire des signaux et systèmes L2S (Supélec, Gif-Sur-Yvette) and at Laboratoire Systèmes Complexes LSC (Evry) in 2004 and 2005. He currently is a Researcher at the Department of Electronic Engineering at the University of Rome "Tor Vergata". His research interests are in robust adaptive nonlinear control with application to electrical machines.
Controllability, maneuverability, fault-tolerance/isolation and safety are significantly enhanced in electric vehicles (EV) equipped with the redundant actuator configuration of four-in-wheel ...electric motors (4IWM). A highly reconfigurable architecture is proposed and illustrated for the adaptive, nonmodel-based control of 4IWM-EVs. Given the longitudinal force, yaw-moment requests and the reconfiguration matrix, each IWM is given a slip reference according to a Slip Vectoring (SV) allocation strategy, which minimizes the overall slip vector norm. The distributed electric propulsion and the slip vector reference allow for a decentralized online estimation of the four-wheel torque-loads, which are uncertain depending on loading and road conditions. This allows for the allocation of four different torques depending on individual wheel conditions and to determine in which region (linear/nonsaturated or nonlinear/saturated) of the torque/slip characteristics each wheel is operating. Consequently, the 4IWMs can be equalized or reconfigured, including actuator fault-isolation as a special case, so that they are enforced to operate within the linear tire region. The initial driving-mode selection can be automatically adjusted and restored among eighteen configurations to meet the safety requirements of linear torque/slip behavior. Three CarSim realistic simulations illustrate the equalization algorithm, the quick fault-isolation capabilities and the importance of a continuous differential action in a critical double-lane-change maneuver.
Adaptive notch filters are local adaptive observers Marino, Riccardo; Tomei, Patrizio
International journal of adaptive control and signal processing,
January 2016, Letnik:
30, Številka:
1
Journal Article
This paper shows that, for a four-wheel steering vehicle, a proportional-integral (PI) active front steering control and a PI active rear steering control from the yaw rate error together with an ...additive feedforward reference signal for the vehicle sideslip angle can asymptotically decouple the lateral velocity and the yaw rate dynamics; that is the control can set arbitrary steady state values for lateral speed and yaw rate at any longitudinal speed. Moreover, the PI controls can suppress oscillatory behaviours by assigning real stable eigenvalues to a widely used linearised model of the vehicle steering dynamics for any value of longitudinal speed in understeering vehicles. In particular, the four PI control parameters are explicitly expressed in terms of the three real eigenvalues to be assigned. No lateral acceleration and no lateral speed measurements are required. The controlled system maintains the well-known advantages of both front and rear active steering controls: higher controllability, enlarged bandwidth for the yaw rate dynamics, suppressed resonances, new stable cornering manoeuvres and improved manoeuvrability. In particular, zero lateral speed may be asymptotically achieved while controlling the yaw rate: in this case comfort is improved since the phase lag between lateral acceleration and yaw rate is reduced. Also zero yaw rate can be asymptotically achieved: in this case additional stable manoeuvres are obtained in obstacle avoidance. Several simulations, including step references and moose tests, are carried out on a standard small SUV CarSim model to explore the robustness with respect to unmodelled effects such as combined lateral and longitudinal tyre forces, pitch, roll and driver dynamics. The simulations confirm the decoupling between the lateral velocity and the yaw rate and show the advantages obtained by the proposed control: reduced lateral speed or reduced yaw rate, suppressed oscillations and new stable manoeuvres.
Occupational stress represents a significant precipitating factor in different diseases but its role in Irritable Bowel Syndrome (IBS) needs to be clarified. The present cross-sectional study aimed ...at investigating the prevalence of IBS diagnosis in a sample of health workers and exploring the potential relationships between IBS, work-related stress levels and work ability.
653 health workers undergoing periodical occupational health surveillance at the Occupational and Preventive Medicine Unit of a major University Hospital in central Italy, were consecutively recruited and screened for IBS diagnosis, according to ROMA IV criteria. The rating scales IBS Severity Scoring System (IBS-SSS), Demand–Control–Support Questionnaire (DCSQ) and Work Ability Index (WAI) were used to assess respectively IBS severity, occupational stress and work ability levels.
IBS prevalence in the sample was 16.8%. Participants suffering from IBS were characterized by a higher prevalence of psychiatric diagnosis and sleep disturbances, higher levels of job strain and isostrain as well as by lower levels of work ability compared to non affected subjects. Moreover, the severity of IBS correlated positively with occupational stress and both were negatively associated with work ability.
The present results suggest the need for preventive, organizational and management strategies at workplace aimed at protecting the health and well-being but also productivity of the worker with IBS.
•IBS was found in 16.8% of 653 healthcare workers (worldwide prevalence of 5%).•IBS healthcare workers show higher levels of job stress and lower of work ability.•Work ability is negatively associated with age, IBS severity and job stress.
The design of exponentially convergent adaptive observers is addressed for linear observable systems which are perturbed by linearly parameterized nonlinearities depending on measured signals (inputs ...and outputs). When there is a lack of persistency of excitation a new robust adaptive observer is presented which performs an additional feedback depending on the kernel of the Gramian of the regressor matrix, which is computed online, and generates state variables estimates whose estimation errors are exponentially convergent to zero, provided that a design parameter is chosen to be sufficiently small. The boundedness of the parameter and observer estimation errors is always guaranteed. Parameter estimates do not converge to their true values unless the regressor matrix is persistently exciting (i.e. the Gramian of the regressor matrix is nonsingular): in this case, a well-known exponentially convergent adaptive observer is reobtained, since the additional feedback is zero.
Machine learning (ML) is increasingly applied in optical network management, especially in cross-layer frameworks where physical layer characteristics may trigger changes at the network layer due to ...transmission performance measurements (quality of transmission, QoT) monitored by optical equipment. Leveraging ML-based QoT estimation approaches has proven to be a promising alternative to exploiting classical mathematical methods or transmission simulation tools. However, supervised ML models rely on large representative training sets, which are often unavailable, due to the lack of the necessary telemetry equipment or of historical data. In such cases, it can be useful to use training data collected from a different network. Unfortunately, the resulting models may be uneffective when applied to the current network, if the training data (the source domain) is not well representative of the network under study (the target domain). Domain adaptation (DA) techniques aim at tackling this issue, to make possible the transfer of knowledge among different networks. This paper compares several DA approaches applied to the problem of estimating the QoT of an optical lightpath using a supervised ML approach. Results show that, when the number of samples from the target domain is limited to a few dozen, DA approaches consistently outperform standard supervised ML techniques.
The adaptive tracking state-feedback control for underactuated mechanical systems with outputs characterized by global relative degree equal to two is addressed. A new control technique called ...virtual control is proposed. Fictitious control inputs and outputs are introduced to achieve full actuation: the key step is to find the reference signals for the fictitious outputs so that the resulting virtual adaptive controls are zero. The adaptive control of an underactuated three-link walking robot with unknown torso mass is designed according to the proposed control strategy. Simulations show that adaptation is crucial for stable walking.
This paper investigates the adaptive error feedback regulation problem for unknown minimum phase, single-input, single-output linear systems with uncertain exosystems. The design problem of a ...feedback control which is capable of driving the output tracking error exponentially to zero, on the basis of the output tracking error only, is locally solved by an adaptive controller which continuously updates the frequency estimates and requires only two informations on the uncertain linear system: (i) an upper bound for the relative degree; (ii) the sign of the high-frequency gain. The proposed adaptive controller contains two gains to be tuned: an adaptation gain which should be chosen sufficiently small and a control gain which should be chosen sufficiently large. Extensions to single-input single-output nonlinear systems affected by uncertain biased multisinusoidal disturbances are outlined.
The problem of global output tracking is addressed for stable minimum phase systems, with constant uncertain parameters and constant disturbances belonging to a known compact set, in the presence of ...input constraints such as amplitude saturation. The relative degree, the system order, and the sign of the high frequency gain are assumed to be known. A hybrid adaptive output feedback control is designed to achieve global asymptotic output tracking, provided that there exists an input within the input constraints capable of tracking exactly the output reference signal. By virtue of the hybrid control approach, the closed-loop system is linear within each time interval between parameter updating. Moreover, no information on input saturation is required by the controller. In addition to the standard assumptions in adaptive control design when inputs are unconstrained, further requirements on the reference signals, on system stability and on parameter bounds, are needed when inputs are constrained.
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