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Poussot-Vassal C.,ONERA | Sename O.,Martin Control Systems | Dugard L.,Martin Control Systems | Savaresi S.M.,Polytechnic of Milan
Vehicle System Dynamics | Year: 2011

This paper is concerned with the synthesis of a robust gain-scheduled H∞ MIMO vehicle dynamic stability controller (VDSC) involving both steering and rear braking actuators. This VDSC aims at improving automotive vehicle yaw stability and lateral performances. The aim of this work is to provide a methodology to synthesise such a controller while taking into account the braking actuator limitations and use the steering actuator only if it is necessary. These objectives are treated in an original way by the synthesis of a parameter-dependent controller built in the LPV framework and by the solution of an LMI problem. The proposed solution is coupled with a local ABS strategy to guarantee slip stability and make the solution complete. Nonlinear time and frequency domain simulations on a complex full vehicle model (which has been validated on a real car), subject to critical driving situations, show the efficiency and robustness of the proposed solution. © 2011 Taylor & Francis.

El Lakkis M.,Martin Control Systems | Sename O.,Martin Control Systems | Corno M.,Polytechnic of Milan | Bresch Pietri D.,Martin Control Systems
2015 European Control Conference, ECC 2015 | Year: 2015

This work presents a modeling and estimation techniques for State of Charge and State of Health estimation for Li-ion batteries. The analysis is done using an adaptive estimation approach for joint state and parameter estimation and by simplifying an existing nonlinear model previously obtained from experiments tests. A switching mechanism between two observers, one for the charging phase and one for the discharging phase, is done to avoid transients due to the discontinuity of model's parameters. Simulations on experimental data show that the approach is feasible and enhance the interest of the proposed estimation technique. © 2015 EUCA.

Alamir M.,Martin Control Systems | Rahmani M.A.,Schneider Electric | Gualino D.,Schneider Electric
Journal of Process Control | Year: 2014

Thermodynamic engines are focusing increasing attention in the context of solar-based electric power generation. Knowledge-based models of such engines are sometimes difficult to derive and when they are available, their simulation may be numerically a rather heavy task given the control updating period that may be needed. In the present work a generic nonlinear identification framework that enables the dynamics of the key quantities of a thermodynamic engine to be captured is proposed. Such a fast model can then be used in the simulation and the control design stage of the whole electric power generation station. The proposed identification framework is validated on a recently developed knowledge-based model of a beta-type Stirling engine with rhomic-drive mechanism. © 2014 Elsevier Ltd. All rights reserved.

Alamir M.,Martin Control Systems
Journal of Theoretical Biology | Year: 2015

This paper proposes a general framework for probabilistic certification of cancer therapies. The certification is defined in terms of two key issues which are the tumor contraction and the lower admissible bound on the circulating lymphocytes which is viewed as indicator of the patient health. The certification is viewed as the ability to guarantee with a predefined high probability the success of the therapy over a finite horizon despite of the unavoidable high uncertainties affecting the dynamic model that is used to compute the optimal scheduling of drugs injection. The certification paradigm can be viewed as a tool for tuning the treatment parameters and protocols as well as for getting a rational use of limited or expensive drugs. The proposed framework is illustrated using the specific problem of combined immunotherapy/chemotherapy of cancer. © 2015 Elsevier Ltd.

Alamir M.,Martin Control Systems
2013 European Control Conference, ECC 2013 | Year: 2013

In this paper, a method is proposed for on-line monitoring of the control updating period in fast-gradient-based Model Predictive Control (MPC) schemes. Such schemes are currently under intense investigation as a way to accommodate for real-time requirements when dealing with systems showing fast dynamics. The method needs cheap computations that use the algorithm on-line behavior in order to recover the optimal updating period in terms of cost function decrease. A simple example of constrained triple integrator is used to illustrate the proposed method and to assess its efficiency. © 2013 EUCA.

Ding H.,Martin Control Systems | Alamir M.,Martin Control Systems | Hably A.,Martin Control Systems
IFAC Proceedings Volumes (IFAC-PapersOnline) | Year: 2014

In this paper, a distributed partially cooperative control framework is proposed for a network of linear interconnected subsystems. It is assumed that each subsystem in the network possesses its own objective and a corresponding nominal interaction-free state feedback law. The proposed framework enables each subsystem to compute an additional control term in order to help maintaining the integrity of the overall network. As this cooperation-like behavior involves relative priority assignment, a communication aware heuristic is proposed with an associated stability assessment that is based on the closed-loop network matrix's spectrum monitoring. Illustrative examples are used to assess the effectiveness of the proposed scheme including a distributed load frequency problem. © IFAC.

Florescu A.,Grenoble Institute of Technology | Bratcu A.I.,Martin Control Systems | Munteanu I.,Martin Control Systems | Rumeau A.,Grenoble Institute of Technology | Bacha S.,Grenoble Institute of Technology
IEEE Transactions on Control Systems Technology | Year: 2015

This paper proposes a general frequency-separation-based strategy of coordinating power sources within off-grid applications. The application chosen to illustrate this strategy is an electric vehicle equipped with two power sources - a battery and an ultracapacitor (UC) - for which coordination problem can be formulated and solved as a linear quadratic Gaussian (LQG) optimal control problem. The two power sources are controlled to share the stochastically variable load according to their respective frequency range of specialization: low-frequency variations of the required power are supplied by the main source, the battery, whereas high-frequency variations are provided by the UC. The studied system is a bilinear one; it can be modeled as a linear parameter varying system. An LQG-based optimal control structure is designed and coupled with a gain-scheduling structure to cover the entire operating range. In this way, load regulation performance and the variations of battery current are conveniently traded off to preserve battery reliability and lifetime. Real-time experiments on a dedicated test rig - based on employing a real UC - validate the proposed optimal power flow management approach. © 2015 IEEE.

Alamir M.,Martin Control Systems | Welsh J.S.,University of Newcastle | Goodwin G.C.,University of Newcastle
Automatica | Year: 2011

In this paper, a new dynamic model describing the epileptic seizure initiation through transition from interictal to ictal state in a brain predisposed to epilepsy is suggested. The model follows Freeman's approach where the brain is viewed as a network of interconnected oscillators. The proposed nonlinear model is experimentally motivated and relies on changes in synaptic strength in response to excitatory spikes. This model exhibits a threshold beyond which a bifurcation toward a short-term plasticity state occurs leading to seizure onset. A resulting explanatory assumption is that when considering epilepsy, brain regions are characterized by abnormally low thresholds toward short-term synaptic plasticity. It is shown by simulation that the proposed model enables some experimentally observed qualitative features to be reproduced. Moreover, a preliminary discussion on the impact of the underlying assumptions on the fundamental issue of seizure control is proposed through an EEG based feedback control scheme. © 2011 Elsevier Ltd. All rights reserved.

Seuret A.,Martin Control Systems | Peet M.M.,Arizona State University
IEEE Transactions on Automatic Control | Year: 2013

This technical brief proposes a new approach to stability analysis of linear systems with sampled-data inputs or channels. The method, based on a variation of the discrete-time Lyapunov approach, provides stability conditions using functional variables subject to convex constraints. These stability conditions can be solved using the sum of squares methodology with little or no conservatism in both the case of synchronous and asynchronous sampling. Numerical examples are included to show convergence. © 1963-2012 IEEE.

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