Patrick Coirault

A harmonic controller of engine speed oscillations for hybrid vehicles

Abstract In conventional internal combustion engines, the periodic fuel combustion in cylinders and oscillating masses result in pulsating engine torque. In hybrid powertrains, the electrical motor can be used to control such pulsations. The main originality of this paper is to present an efficient harmonic controller synchronized with the engine speed: the feedback law controls the Fourier parameters of the command. For time-variation of the engine speed, the adaptation of the harmonic controller ensures the convergence of the command. Conditions of stability are given, and the robustness of the approach is presented. Simulation shows that the undesirable harmonics of engine speed oscillations are perfectly rejected in spite of engine speed variation.

Adaptive rejection of the preponderant harmonic of a pulsed flow

Pulsed flows, characterized by periodic fluctuations in flow rate, are noise-productive, but an oscillating valve positioned in the exhaust duct can attenuate the main harmonic of pulsed flow. We define a valve adaptive control in the frequency domain implemented by a digital signal processor for experimental purposes. Results show noise reduction at ground level and tracking of process unstationarity.

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.

Masked Symmetric Chaos Shift Keying : Modulation and demodulation of Chua's circuits using PI control estimated from LMI criterion

This paper deals with a new modulation technique based on symmetric chaos shift keying (SCSK) and its receiver structure is described for optimal synchronization. The masked symmetric chaos shift keying (MSCSK) improves both security of information signal compared to SCSK and demodulation procedure. Optimal synchronization of two identical chaotic systems is performed in the paper. By using dissipativity theory, a PI control system is proposed according to linear matrix inequality (LMI). The coefficients of PI are resolved using the MATLAB LMI Toolbox. 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 scheme

The Repeated Least Squares Identification Method : A New Approach Based on Discrete Moments

Abstract A new approach is used to revise an old identification algorithm, the Repeated Least Squares method, for the model order and parameter estimation. This technique use an overparametrized model, based on discrete moments. An optimal criterion is then introduced, allows to choose an optimal model order.

Coherent Synchronization of a Chaotic Communication System Based on a QAM-4 Transmitter

Remarkable research efforts have been invested in recent years on the chaotic communications schemes. In this paper we propose a modulation technique based on QAM-4 (Quadrature Amplitude Modulation). The data is split into I and Q channels. Each channel is spread by chaotic sequences generated over a fixed time interval by a specific digital chaotic system. There are two principal advantages of introducing the chaos in a communication scheme. The first is that it allows signals to be transmitted in a secure way, so that the signal could be perceived as a noise for a potential intruder. Secondly, the spread-spectrum characteristics of the signal improve the noise rejection propreties. A new coherent receiver structure is presented to synchronize each channel. Simulation results are presented to show the effectiveness of the proposed scheme.

Overparametrization: A Tool for System Identification

Abstract This paper deals with the identification of linear systems using overparametrization techniques. Several algorithms are developed in order to reduce overparametrization order. Model order reduction is studied in finite and large order system case using moments.

Potential Feedback Control for the Power Control in LTE

This technical note deals with the study of uplink (from the mobile phone to the base station) transmitted power control in Long Term Evolution (LTE). It provides a nonlinear Potential Feedback Control (PFC) for scalar discrete-time systems with input delays and disturbances by using the Lyapunov theory and the Artstein transform. It is an original approach in which a stabilization problem of a linear scalar system with a constraint on the state space is transformed into a problem of nonlinear stabilization. We use this strategy of stabilization for the uplink transmission power control in LTE.

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.