Giampaolo Usai's research while affiliated with Università degli studi di Cagliari and other places
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Publications (28)
In this paper we present an original design procedure for semiactive suspension systems. Firstly, we consider a target active control law that takes the form of a feedback control law. Secondly, we approximate the target law by controlling the damper coefficient f of the semiactive suspension. In particular, we examine two different kinds of shock...
This paper derives a linear model of open channels enabling to design a decentralized volume variations observer. The proposed observer allows to implement decentralized constant volume controllers under the realistic assumption of non-measurable state. The main advantage of this approach is that each state variable may be reconstructed on the base...
In this paper we present a design procedure for semiactive
suspensions of road vehicles. In the first phase we design an asymptotic
state observer that reveals to be particularly efficient in the presence
of external disturbances. We also derive a target active control law
that minimizes a quadratic performance index and takes the form of a
feedbac...
In this paper we realize the design of an active--passive suspension system for the axletree of a road vehicle based on a linear model with four degrees of freedom. The optimal control law we propose aims to optimize the suspension performance while ensuring that the magnitude of the forces generated by the two actuators and the total forces applie...
Inthis paper we realize the design of a mixed suspension system(an actuator in tandem with a conventional passive suspension)for the axletree of a road vehicle based on a linear model withfour degrees of freedom. We propose an optimal control law thataims to optimize the suspension performance while ensuring thatthe magnitude of the forces generate...
We consider a linearized parameter-varying model of a planar crane and show how a controller can be designed, following the state-feedback stabilization technique for time-varying systems proposed by Wolovich. The resulting closed-loop system is equivalent, via a Lyapunov transformation, to a stable time-invariant system of assigned eigenvalues. We...
The paper presents a two-phase design technique for semiactive suspensions. In the first phase, we use a procedure proposed by Yoshida et al. to compute a target active control law that can be implemented by Optimal Gain Switching. This control law is such that the force generated by the suspension system is bounded within a set U. In the second ph...
A lumped-parameter model is considered for open-channel networks
that expresses the dynamic relationship, in terms of state space
variables, between gate opening sections and stored water volume
variations in the different canal reaches with respect to a reference
configuration of uniform flow. A procedure is suggested to approximate a
real steady...
The paper presents a two-phase design technique for semiactive
suspensions. In the first phase, we use a procedure proposed by Yoshida
et al. (1986) to compute a target active control law that can be
implemented by optimal gain switching. This control law is such that the
force generated by the suspension system is bounded within a set. In the
seco...
To improve the efficiency of cargo handling with cranes it is
necessary to control the crane trolley position so that the swing of the
hanging load is minimized. In this paper we consider a linear
parameter-varying model of the crane, where the time-varying parameter
is the length of the suspending rope. We consider the set of models
given by froze...
A relatively simple class of parametric dynamic models for simulating the growth of unevenaged forest stands, expressed in terms of diameter classes, is presented and discussed. The problem of model validation towards the available growth data is formulated as a non-linear multipoint boundary value problem and solved via a heuristic iterative proce...
Optimal design of an active suspension system for road vehicles can be solved using LQR techniques. Such a problem is equivalent, in the frequency domain, to determine the state feedback gain matrix that minimizes the H2 norm of a suitable transfer matrix.A passive suspension system can be seen as the physical realization of a suitable state feedba...
The paper presents a gain-scheduling approach to the control of a
high-speed train pantograph. The feed-back law design is based on
optimal control with frequency dependent cost functionals. Two active
control schemes are discussed. Nonadaptive frequency-shaping control
gives good performances for disturbances in a wide range of frequencies.
Distur...
A procedure is proposed for calculating the parameters characterizing the transfer function of an actual vibration damper for overhead transmission line conductors, based on the preliminary determination of an ideal target transfer function derived from energetic considerations. The procedure involves choosing and minimizing a suitable performance...
The authors examine the problem of the synthesis of an optimal
control law for active suspensions of road vehicles, based on a model
with two degrees of freedom. The possibility of realizing the desired
optimal control law with a tandem active-passive suspension is
considered. The procedure for determining the desired optimal control
law on the bas...
A mathematical model is presented for open-channel networks that expresses the dynamic relationships, in terms of transcendental transfer functions, between the gate opening sections and the corresponding stored water volume variations in the different canal reaches with respect to an initial reference condition of uniform flow. Series expansion ar...
A control method which, through the suitable servo-operation of the check gates, attains a consistent improvement in the speed of response of hydroelectric power canals is presented. Its application allows the size of the canal headpond to be reduced at the design stage of the power station as well. The proposed method is based on the constant volu...
An optimal time control problem arising in forest stand management is presented. The paper refers to a nonlinear dynamic model, expressed in terms of diameter classes, of the growth of a Mediterranean forest stand. The problem is tackled by resorting to the Pontryagin maximum principle and is thus reduced to a two-point boundary value problem. Bein...
The purpose of this work is to summarize the findings of studies conducted by the authors on the problem of modelling and control of open channel networks published in recent years. In the case of open channels, where flowrates control is not technically recommended (as it gives rise, in the long run, to drift phenomena), the controlled quantities,...
A state variable mathematical model for use in the synthesis of automatic control systems for open-channel networks is presented. The system considered here consists of n-cascaded reaches joined by control gates.The linear time invariant model consists of a controllable and observable representation where the state variables are the stored water vo...
A constant volume control technique for the operation of open channel networks is proposed. Such a technique is based on the evaluation of stored water variations in each reach, relative to a uniform flow reference configuration, through water level measurements at the upper and lower end of each reach which set up the error signals for the feedbac...
A distributed parameter mathematical model for the study of hydraulic transients in canal reaches of conveyance open-channel networks equipped with AMIL gates is presented. The model derives from the linearization of the Saint-Venant equations for the unsteady flow of water in open channels and provides, thanks to a simple approximation of frequenc...
A procedure is presented for deriving a mathematical model for canal networks for irrigation, municipal and industrial uses. Such a model allows one to determine the hydraulic transient between two steady state situations, assuming a succession of steady flows and accounting for time delays due to the propagation of perturbations. This study is par...
As a further step in the research about the differential heating phenomenon in large induction motors with deep rotor bars, a testing model of a rotor bar has been built up; thanks to the model it has been possible to simulate the thermial behavior of deep bars in standstill.
The paper describes a formal procedure to construct a Petri net model starting from the difier-ential equations that describe the behavior of a canal network. In a first approach, the equations are discretized and the corresponding model takes the form of a deterministic timed Petri net. In a second approach, timed continuous Petri nets are used. T...
We consider a linearized parameter-varying model of a planar crane and show how a controller can be designed, following the state-feedback stabilization technique for time-varying systems proposed by Wolovich. The resulting closed-loop system is equivalent, via a Lyapunov transformation, to a stable time-invariant system of assigned eigenvalues. We...
Citations
... The constant downstream depth method is mostly used in long distance canal systems because it could greatly reduce investment and is simple for operators' use. The constant volume method is used in the Central Arizona Project in U.S.A. to avoid mismatch of flows at the two ends of aqueducts [3,4], but is seldom used for long distance water diversion projects in China for its complexity and requirements for simultaneous operation of all pumps and check gates. ...
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... Even at Bulacan State University-Sarmiento Campus, there is a paucity of lighting systems in various places of the campus at night, resulting in uncomfortable and unsafe situations for students and campus workers. With this concern in mind, the researchers devised a waterwheel system (Corriga et al., 1988) that can generate electricity to power lighting equipment, thereby assisting students and campus personnel by creating light to make them feel safe and comfortable on campus premises. The study's goal is to build a water wheel device in an artificial pond (Linares et al., 2023) to generate free energy to power lighting gadgets (Tawalbeh et al., 2023) and to promote ecofriendliness among people. ...
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... Las investigaciones desarrolladas en diferentes canales principales de riego muestran que sus parámetros dinámicos experimentan grandes variaciones cuando sus regímenes de descarga varían en el rango de operación [Q mín , Q máx ] y/o otros parámetros hidráulicos cambian (Corriga et al., 1989;Litrico y Fromion, 2009;Montazar et al., 2005;Rivas-Pérez et al., 2007). Esta clase de canales se conoce como canales con parámetros dinámicos variables en el tiempo (Litrico et al., 2006;Rivas-Pérez et al., 2008b). ...
... El control óptimo desarrollado en la segunda mitad del siglo XX y aplicado fundamentalmente en el control de naves espaciales [103,104] ha sido sugerido para el control de la distribución de agua en los canales de riego, ver por ejemplo [105][106][107][108][109][110][111][112]. Esta estrategia de control generalmente requiere de un modelo del proceso en variables de estados obtenido analíticamente o mediante identificación de sistemas [103]. ...
... Models of this kind can be found in the literature for different systems, e.g., for traffic systems in[36] and for irrigation systems in[37]. ...
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... The first discretizes the SVEs either explicitly, in which instability may occur concerning the applied spatial discretization scheme (Vrugt et al., 2003), or implicitly, with the Preissmann scheme, which is stable regardless of the spatial discretization (YoosefDoost & Lubitz, 2021). The transformation models are as follows: Hayami (1951) model, in which the SVEs are linearized by analysing flowing water in the watercourses; Corriga et al. (1980) model, which presents an analytical solution to calculate water depth and flow under steady flow using Laplace transformation and takes into account the average values of the hydraulic parameters; integrator delay zero (IDZ) model, proposed by Mehdy Hashemy Shahdany and Roozbahani (2016), in which water depths and flows are inputs and outputs, respectively, since the SVEs' linearized Laplace transform has a spatial linear ordinary differential (Shahdany et al., 2018); and nonuniform IDZ, which is similar to IDZ, in which flows are outputs and regulators' positions are inputs (Shahdany et al., 2018). In the orthogonal collocation models, the inertia term in the SVEs is neglected. ...
... Another state-space MIMO model was used in Seatzu (1999Seatzu ( , 2000 and Seatzu and Usai (2002). In that case the modeling was performed around a particular hydraulic regime, called uniform regime that is the only one that has an algebraic solution by linear zing the Saint-Venant equations. ...
... Tavares has studied theoretically about water distribution network. He has developed nonlinear dynamical models and controllers to monitor the level of the water in the canal system of NuHCC [5]. Because of diverse and comprehensive literature, it was examined only the water channel networks and control of water levels and pressure. ...
![[object Object]](https://i1.rgstatic.net/ii/profile.image/838102000099334-1576830496933_Q64/Alessandro-Giua.jpg)
... To establish the limits between which the values of the elastic and damping constants can vary, a dynamic model with 4 degrees of freedom will be presented. This model can be used for a control strategy of semi-active suspensions [8], [9]. Figure 1 shows the model of a front drive axle with suspension with helical springs, type MacPherson, in a certain position. ...
Reference: Dynamic model for an independent suspension
... Li and Pin [1] employed evolutionary algorithms to optimize a passive quarter-car suspension. Optimization of a quarter-car suspension is formulate as an H2 optimal control problem by Corriga et al [2] and a simplex direct search is employed to find the optimum values of two parameters. Camino et al [3] apply a linear-matrixinequality (LMI) base min/max algorithm for static output feedback to design of passive the optimal quarter-car suspension. ...
