Sebastien Cauet

A 2.4 GHz 1-dimensional array antenna driven by vector modulators

This paper aims to develop an intelligent radio-communication prototype using multiple-antenna phased array whose bearing can be controlled electronically. Such a system has proved its efficiency in terms of gain and SNR improvement. The architecture presented in this article runs at 2.4 GHz with a bandwidth channel of 11 MHz which is well suited for WIFI 802.11b applications. This original system uses quadrature modulators as active phase-shifters, and noise sensitivity is studied and simulated to prove the interest of this architecture. A circuit is under tests and first elementary active parts RF measurements are given.

SYNCHRONIZATION OF TWO CHAOTIC SYSTEMS USING PID CONTROL

Abstract This paper deals with the state reconstruction of nonlinear chaotic systems. Application is related to chaos synchronization between two identical systems for secure communication. An information message is injected into a chaotic system by modulating a chosen parameter. In the receiver, a linear PID controller is designed based on dissipativity theory to ensure global chaos synchronization of the two systems. The proposed controller is simple and can be easily implemented in the demodulator. Simulation results are presented for the Chua circuit and show the effectiveness of the proposed chaos synchronization scheme.

Parameter-dependent Lyapunov functions applied to analysis of induction motor stability

Abstract The problem of robust stability of an induction motor is analysed in this paper. A classical feedback linearization (not detailed here) based on a nominal model is used to get a linear model to be studied. When uncertainty is taken into account, this model exhibits two features: first, it is subjected to a time-invariant polytopic uncertainty. Second, it has an additive nonlinear uncertainty. The main contribution of this paper lies in the stability analysis in the presence of both uncertainties. To enlarge the uncertainty domain, the size of the acceptable nonlinear uncertainty is maximized under stability constraints involving parameter-dependent Lyapunov functions.

Robust control and stability analysis of linearized system with parameter variation application to induction motors

This paper discusses the synthesis and the analysis techniques applied to a nonlinear system subjected to parameter variations for which an exact feedback linearization is performed. The obtained linear system is described by a linear and a nonlinear dependant parameter parts. An H/sub 2//H/sub /spl infin// robust output feedback controller is designed on the linear part. The effect of the nonlinear part is attenuated by means of a reference model. A stability analysis method using parameter-dependant Lyapunov function is used to check the global stability in the presence of the nonlinearity which has been ignored in the synthesis step. The synthesis and the analysis results are then applied to an induction motor.

LPV Control of ICE Torque Ripple in Hybrid Electric Vehicles

Abstract In this paper, a linear parameter varying (LPV) control strategy is implemented in order to reduce torque ripple in Hybrid Electric Vehicles (HEV). The Internal Combustion Engine (ICE) ripples are attenuated by a Permanent Magnet Synchronous Machine (PMSM). Because the ICE motor generates persistent disturbances which vary with the rotational speed, it is necessary to design a LPV controller. The control strategy uses the internal model principle. The controller is designed by several steps which includes linear matrix inequalities optimization (LMIs). A test bed simulator is used through a complete modeling of a hybrid powertrain propulsion. Simulation results show the effectiveness of the control.

On the stabilization of a class of periodic positive discrete time systems

This paper investigates the stabilizability of a class of linear periodic discrete-time systems for which the state vector complies with a positivity constraint. LMI-based conditions for the existence of a desired periodic state feedback controller guaranteeing the resultant closed-loop system is asymptotically stable and positive are presented. The obtained results are then extended to the problem of stabilizability and positivity of linear periodic system in presence of polytopic parameter uncertainty. Numerical examples are provided to illustrate the proposed conditions.

Torque harmonic reduction in hybrid vehicles

In this paper, the authors propose a novel control strategy of torque ripple reduction in hybrid vehicles. The Internal Combustion Engine (ICE) ripples are reduced by an active filter and a Permanent Magnet Synchronous Machine (PMSM). This electric motor is mounted on the crankshaft in order to generate a torque sequence opposing ripple torque. The control strategy is based on a static output feedback synthesis. The problem is reformulated in the time domain with regard to the main order of the fluctuations. An hybrid propulsion complete modeling is achieved from an experimental benchmark. The model is performed at low speed (900 rpm). In fact, at this speed, the ripple is very restrictive. Simulation results highlight the control approach interest.

Soft sensor design for oil temperature in distribution transformer (type ONAN)

This paper contains a review of a thermal model of transformer published by standard organization IEC on the estimation of the oil temperature for a distribution transformer type ONAN by adding a method to identify certain parameters which are difficult to know their precise values from only technical or normative information.

Time-Varying Delay Passivity Analysis in 4 GHz Antennas Array Design

In this paper, a new approach for synchronization of dynamical networks with time-delays is proposed. It is based on stability theory of coupled time-delayed dynamical systems. Some new criteria for stability analysis which ensure the synchronization of the networks are analytically derived. Conditions for synchronization, in the form of Linear Matrix Inequality, are established. They use the Lyapunov and Krasovskii stability theories. In this approach, parameter uncertainties are introduced in the network model. Numerical simulations show the efficiency of the proposed synchronization analysis. A network of 4-GHz smart antenna array is used and analyzed in some details. This array provides a control of the direction of the radiation pattern.

Persistent disturbances rejection on Internal Combustion engine torque in Hybrid Electric Vehicles

In this paper, a new control strategy of torque ripple reduction in Hybrid Electric Vehicles (HEV) is presented. The Internal Combustion Engine (ICE) ripples are reduced by a Permanent Magnet Synchronous Machine (PMSM). The control strategy uses the internal model principle. It is based on dynamic output feedback controller synthesis. The controller design problem is reduced to solving a system of linear matrix inequalities (LMIs). It is formulated in the time domain with regard to the main order of the fluctuations. A test bed simulator is developed through a complete modeling of a hybrid powertrain propulsion. Simulation results show the control approach interest.