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The following topics are dealt with: pendubot; decentralized closing ranks; adaptive control; SISO feedback systems; centralized control systems; second-order linear descriptor differential system; rendezvous AUV trajectories generation; payload derived position system; attitude system acquisition; tracking control; time delay; game ship control; double pendulum; three tank system; time-varying sliding...
Numerous physical processes are modeled by partial differential equations and are often instrumented with boundary actuators and sensors. A major new effort has been underway in recent years to develop constructive designs of boundary control laws for unstable PDE systems. This development draws upon the ideas of "backstepping" synthesis for nonlinear ODEs from the 1990s and is an infinite-dimensional,...
In recent years there has been a great effort to convert the existing air traffic control system into a novel system known as Free Flight. Free Flight is based on the concept that increasing international airspace capacity will grant more freedom to individual pilots during the enroute flight phase, thereby giving them the opportunity to alter flight paths in real time. Under the current system pilots...
The problem of time optimal magnetic attitude control is treated and an open loop solution is first obtained using a variational approach. In order to close the control loop, a neural network with time varying weights is proposed as a feedback optimal controller applicable to the time varying nonlinear system. The good robustness and low real-time computational burden of the proposed neuro-controller...
A robust asymptotic output command tracking controller is proposed to control the longitudinal motion of an aircraft model involving atmospheric gusts. The controller covers various flight conditions. The stability derivatives of the aircraft and the velocity of the aircraft are considered to be uncertain parameters. The output of the closed loop system tracks step and ramp type reference signals...
This paper deals with the position and attitude control of a Vega-type space launcher. The first part of the paper develops a general model of the launcher that takes into account the gravity, air density and mass variation. It also derives a linear model with uncertainty for the dominant dynamics, taking the nonlinear characteristics of the system as parametric uncertainty. The second part introduces...
A nonlinear suboptimal guidance scheme is developed for the reentry phase of the reusable launch vehicles. A recently developed methodology, named as model predictive static programming (MPSP), is implemented which combines the philosophies of nonlinear model predictive control theory and approximate dynamic programming. This technique provides a finite time nonlinear suboptimal guidance law which...
In this paper a nonlinear optimal controller has been designed for aerodynamic control during the reentry phase of the reusable launch vehicle (RLV). The controller has been designed based on a recently developed technique optimal dynamic inversion (ODI). For full state feedback the controller has required full information about the system states. In this work an extended Kalman filter (EKF) is developed...
In this paper Fisher's discriminant analysis (FDA) is used for detecting and diagnosing faults in a real plant. FDA provides an optimal lower dimensional representation in terms of discriminating between classes of data, where, in this context of fault diagnosis, each class corresponds to data collected during a specific, known fault. A discriminant function is applied to detect and diagnose faults...
Principal component analysis (PCA) is a powerful fault detection and isolation method. However, the classical PCA which is based on the estimation of the sample mean and covariance matrix of the data is very sensitive to outliers in the training data set. Usually robust principal component analysis was applied to remove the effect of outliers on the PCA model. In this paper, a fast two-step algorithm...
In multivariate statistic process control (MSPC), the projection methods, in particular, the principal component analysis (PCA) proved their efficiencies to the problems of fault diagnosis. In this paper, we explained the use of this tool and its major interest. A projected observation in the PCA space has a score distance (SD) in the principal component subspace and an orthogonal distance (OD) or...
In this paper, a fault tolerant control (FTC) system based on data driven fault detection (FDI) is presented. The behaviour of the system with proactive and reactive FTC strategies is studied in the presence of faults in an online product quality analyser with a simulated dearomatisation process operated under model predictive control (MPC). The performance of the system is validated onsite at the...
Precise identification of structural properties is a vital step towards detection and localization of damage in structures. In this paper the problems of improving accuracy of modal parameter estimates and automatic elimination of spurious modes in covariance driven output-only subspace identification method are addressed. An iterative procedure is proposed, which in the first step, actively modifies...
This paper outlines a formation control strategy for maneuvering a team of nonholonomic robots within a mapped environment. The major contribution of this work is an exploration of when formation changes should occur. We approach this problem using a two step process. First, a hybrid controller is designed which can follow a set of waypoints while switching between a group of formations based on the...
Switched and piecewise affine models are interesting when modeling a nonlinear and non stationary complex system. Identification of these models is a challenging problem that involves estimation of both the parameters of the submodels, and the partitioning of state and input space. In this paper, we introduce a subspace technique for identification of the class of multi-variable hybrid complex system...
This paper deals with hybrid observer design for state switched systems described by differential Petri nets (DPN). The structure herein proposed is composed of a discrete observer and a continuous observer that are in interaction. The discrete observer reconstructs the discrete mode, by estimating both of the discrete marking and the firing vectors. Once, the active mode is obtained, the continuous...
We present a new framework for describing multi-agent systems with hybrid individual dynamics where the interaction between agents occurs at both the continuous and discrete levels. We formally define these multi-agent systems as interconnected hybrid systems and then recast fundamental hybrid concepts such as a hybrid metric, hybrid execution, and reachability in this new interconnected hybrid systems...
This paper deals with discrete-time systems and considers the problem of computing an upper bound to the dwell time of switched systems ensuring a pre-specified root mean square gain (RMS). As a natural consequence of treating general systems of this particular class in terms of the order and the number of subsystems, only sufficient conditions are worked out. However, as positive features, they are...
In this paper the Switched Linear Internal Model (SLIM) controller, an Internal Model based control scheme recently proposed by the authors, is qualitatively analyzed in terms of sensitivity to external disturbances. This investigation is particularly relevant to motivate further efforts toward a theoretical assessment of the considered scheme. In fact, SLIM solution is expected to have good robustness...
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