Showing papers by "Georges Bastin published in 1991"
TL;DR: The dynamics of non holonomic mechanical systems are described by the classical Euler-Lagrange equations subjected to a set of non-integrable constraints as mentioned in this paper, which cannot be asymptotically stabilized by a smooth pure state feedback.
Abstract: The dynamics of non holonomic mechanical system are described by the classical Euler-Lagrange equations subjected to a set of non-integrable constraints. Non holonomic systems are strongly accessible whatever the structure of the constraints. They cannot be asymptotically stabilized by a smooth pure state feedback. However smooth state feedback control laws can be designed which guarantee the global marginal stability of non holonomic systems.
175 citations
09 Apr 1991
TL;DR: A general dynamical model is derived for three-wheel mobile robots with nonholonomic constraints by using a Lagrange formulation and differential geometry and it is shown that a static state feedback allows one to reduce the dynamics of the system to a form in which stabilizing input-output linearizing control is possible.
Abstract: A general dynamical model is derived for three-wheel mobile robots with nonholonomic constraints by using a Lagrange formulation and differential geometry. It is shown that a static state feedback allows one to reduce the dynamics of the system to a form in which stabilizing input-output linearizing control is possible. >
136 citations
TL;DR: An overview of the various parametric approaches which can be adopted to solve the problem of adaptive stabilization of nonlinear systems is presented in this article, where the Lyapunov design and two estimation designs are revisited.
Abstract: An overview of the various parametric approaches which can be adopted to solve the problem of adaptive stabilization of nonlinear systems is presented. The Lyapunov design and two estimation designs —equation error filtering and regressor filtering— are revisited. This allows us to unify and generalize most of the available results on the topic and to propose a classification depending on the required extra assumptions — matching conditions or growth conditions.
127 citations
TL;DR: Simulations show the robustness of the proposed traffic control algorithms against disturbances occurring randomly on a loop line and their efficiency when compared to a classical time margin strategy.
Abstract: A complete traffic analysis for sequential metro lines with or without reference to a nominal time schedule is developed. The intrinsic instability of metro lines is pointed out. It is shown how well-chosen state-space formulations allow design of state-feedback control algorithms ensuring the stability of the system. The proposed traffic control algorithms have simple forms and are easy to implement in real-life systems. Simulations show the robustness of the proposed traffic control algorithms against disturbances occurring randomly on a loop line and their efficiency when compared to a classical time margin strategy. >
114 citations
11 Dec 1991
TL;DR: The dynamics of nonholonomic mechanical systems are described by the classical Euler-Lagrange equations subjected to a set of nonintegrable constraints as discussed by the authors, and smooth state feedback control laws can be designed which guarantee the global marginal stability of the system with the convergence to zero of an output function whose dimension is the number of degrees of freedom.
Abstract: The dynamics of nonholonomic mechanical systems is described by the classical Euler-Lagrange equations subjected to a set of nonintegrable constraints. It is shown that nonholonomic systems are strongly accessible whatever the structure of the constraints. They cannot be asymptotically stabilized by a smooth pure state feedback. However, smooth state feedback control laws can be designed which guarantee the global marginal stability of the system with the convergence to zero of an output function whose dimension is the number of degrees of freedom. >
97 citations
11 Dec 1991
TL;DR: In this article, the authors address the problem of the reduction of order of natural mass-balance models which commonly describe the dynamics of reaction systems and propose a convenient change of coordinates which is better suited to perform the order reduction.
Abstract: The authors address the problem of the reduction of order of natural mass-balance models which commonly describe the dynamics of reaction systems. This reduction is subordinated to the presence of slow and fast reactions. it is shown that, in natural coordinates, a convenient partition of the state leading to a two-time-scale standard form which allows the order reduction by using the singular perturbation technique does not generally exist. A convenient change of coordinates which is better suited to perform the order reduction is proposed. A systematic method is presented for transforming the natural mass-balance model of reaction systems with slow and fast reactions into the two-time-scale standard form of singular perturbation theory. The theory is illustrated by a prototype example. >
59 citations
11 Dec 1991
TL;DR: The authors present a general methodology for the design of adaptive regulators for fed-batch biological reactors with the aid of an illustrative case study which has given rise to a genuine industrial application.
Abstract: The authors present a general methodology for the design of adaptive regulators for fed-batch biological reactors with the aid of an illustrative case study which has given rise to a genuine industrial application. The application under consideration is the feedback optimization of yeast fermentations, which are of particular interest because yeasts are among the most frequently used microorganisms in genetic engineering for the production of high added value metabolites. The case study is representative of a wide class of control problems in biotechnology where the regulation of some substrate or metabolite concentration helps to solve yield/productivity conflicts. >
10 citations
09 Apr 1991
TL;DR: An original procedure for the estimation of the barycentric parameters of a robot is presented, based on the property that the relations between the robot motion and its reactions on its bedplate are completely independent of the internal joint forces.
Abstract: An original procedure for the estimation of the barycentric parameters of a robot is presented. This procedure requires only the processing of measurements provided by an external experimental set-up (reactions at the bedplate, and position, velocities, and accelerations). The procedure is based on the property that the relations between the robot motion and its reactions on its bedplate are completely independent of the internal joint forces. Some identifiability issues are discussed, and a validation experiment is reported. >
9 citations
01 Jan 1991
TL;DR: In this article, an adaptive linearizing and L/A control strategy using as control input either the dilution rate or the influent bicarbonate is proposed to stabilize anaerobic digestion processes.
Abstract: Proposes efficient bicarbonate control strategies for anaerobic digestion processes. The bicarbonate concentration which is easier and cheaper to measure than volatile acids concentration is regulated in order to stabilize the process. Adaptive linearizing and L/A control strategies using as control input either the dilution rate or the influent bicarbonate are proposed. The controllability properties of both inputs for the assumed nonlinear mathematical model are analyzed through linearization around steady-states. Simulations results are presented and discussed.
8 citations
TL;DR: In this paper, necessary and sufficient conditions for the identification of a vector θ of unknown parameters in scalar dynamical systems of the form x = f (x, θ) + g(x, u), where f(x and u) is a polynomial function of the state x that is affine in θ, and g(ex, u, x) is an affine function of state x and the input u.
8 citations
TL;DR: In this article, a branch-and-bound approach to system identification is described and justified, which allowed the authors to reduce significantly the number of model structures investigated by their expert system for process identification.
01 Jan 1991