Personal research




Research in the framework of the group CO2

Control and scientific Computing


of the CNRS lab CRIStAL,UMR 9189 (INS2I)

Centre de Recherche en Informatique, Signal et Automatique de Lille



Main topic: theory and applications of time delay systems (see more details below).

Supervised PhDs: see publications



Time-Delay Systems theory:

Surveys: time-delay systems [RI/03/41], aperiodic sampling [RI/17/78]

Homogeneity for TDS: nonlinear homogeneity [RI/14/67][RI/16/72], finite-time stabilty [RI/14/68][RI/16/72], Implicit Lyapunov-Krasovskii Functionals [RI/15/71]

Delay identification: identifiability [RI/02/33][OC/04/25], algebraic identification [RI/10/55][RI/09/53][CI/08/113][CI/07/108][CI/06/099][CI/06/101][CI/06/102], variable structure identification [RI/06/46][CI/04/086][RI/03/38]

Estimation / observation: interval observers [RI/13/63][RI/15/70][RI/16/78], output feedback with unknown input delays [RI/13/63][CI/07/109][CI/07/107][CI/06/097] or unknown input [RI/16/73][RI/11/58], estimation under data-rate constraints [CI/20/186] [CI/21/187], algebraic estimation of multivariate derivatives [RI/11/59][CI/11/129]

Asynchronous sampling: survey [RI/16/77], state-dependent sampling [RI/15/69][RI/12/61][TH/12/27], nonlinear systems [RI/14/65][CI/12/143][CI/12/136], input delay approach [RI/04/44], hybrid systems / dissipativity approach [RI/21/92][RI/14/65][RI/11/57][RI/13/65][TH/14/28], frequency domain [RI/21/91]

Networked control / observation: variable delays, remote (predictive) observer for control [CO/08/28][CI/09/117][CI/08/115][CI/08/114][CI/06/1][TH/06/19]

Stability and stabilization of TDS: linear systems with sampling [RI/15/69][RI/11/56] or discrete/distributed delays [RI/99/24][RI/99/23]; nonlinear systems [TH/06/21][OC/97/19][RI/97/16], exponential stabilization [TH/06/19][CI/04/088], finite time stabilty [RI/14/68][RI/16/72], Implicit Lyapunov-Krasovskii Functionals [RI/15/71]

Neutral systems: interval techniques [RI/15/70], LKF aproach [RI/11/55] or positive systems [RI/98/20]

Positive systems and constrained control: positive comparison systems and vector norm approach [RI/95/12][RI/97/18][OC/03/24], Metzler matrices [RI/96/14]

Relay-delay systems : sliding mode under delay (LMI criteria) [RI/01/30][RI/03/37] and nonlinear extension [RI/06/45], deadzone and delay [RI/07/49]

Discretization and computational aspects: distributed delay realization (finite spectrum assignment) [CI/01/76][CI/99/059]

Infinite dimensional systems: interval observers for PDEs and delay systems [TH/19/30][RI/18/81][RI/20/86]


Applications :

Fluid mechanics: control of turbulent separated flows, closed loop sliding mode control via nonlinear time-delay models - applications to aeronautics and ground transportation in the framework of the ELSAT2020 program. Papers [RI/20/85][RI/19/84][RI/17/79][CI/16/161] and patent [PAT/17/1]. See also (in French)

Distributed systems: robust decentralized controllers [RI/18/83], distributed fast estimation [RI/18/82], asynchronous control [RI/21/91][RI/21/92], data-rate constraints [CI/20/186] [CI/21/187] - in the framework of the UCoCoS H2020 European project

Remote control over unreliable networks: using  non dedicated networks (Internet, Wifi) for bilateral teleoperation [RI/14/64][CI/12/137][CI/11/134][TH/12/26] and remote control [RI/12/60][TH/09/24][TH/06/19]

Collaborative robotics: unicycle robots [CI/21/187], wheeled robots (jointly with LIRMM and CRAN - Region Nord Pas de Calais) [CI/04/091]

Service robotics: evolutive autonomous wheelchair, European project Sysiass (see also communique de presse)

Aeronautics: identification of a flight model (jointly with ONERA) [TH/06/20][CI/06/7]

Image: multivariate differentiation for image processing [RI/11/59]

Transports : automated transportations (within GRAISyHM CPER) [RC/04/10]

Biology: meta-dynamics for population models [RI/07/48][CI/03/083][CI/02/077], molecular models (jointly with IRI - IBL) [TH/07/22]

Agri-food: spray boom pressure control [RI/07/49][CI/04/085][CI/05/093] (jointly with LAMP Leuven), mixing tank control (jointly with LAGIS and INRA) [CI/01/072][CI/03/084][RF/03/36]

Underactuated mechanics: inverted pendulum [RI/08/51][RI/08/52][TH08/23]


Ongoing projects and networks

ANR Finite4SoS: Finite-time Control and Estimation for Systems of Systems -

CPER ELSAT2020, CONTRATECH project: interdisciplinary program on technologies for flow control -

other team's projects can be found at


Previous rechearches and projects:

H2020 UCoCoS: Understanding and Controling Complex Systems -

InterReg SYSIASS: Autonomous and Intelligent Healthcare System -
Highly-complex and networked control systems -
European GDRi DelSys (2011-2015):
Time Delay Systems -
ADT SENSROB: Robotics and Wireless Sensor and Actuator Networks - http://sensas.gforge.inria.frVolterra difference equations:
estimation of the solutions [RI/02/34], stability [RI/00/26] (collaboration V.B. Kolmanovskii, MIEM, Moscou)

Stability of nonlinear systems, positive systems: state-space transformations [OC/92/13], constrained stabilization [RI/96/15][RI/96/14], positive comparison systems and vector Lyapunov functions [OC/03/24], Metzler matrices [RI/96/14] (see extensions to delayed cases in [RI/13/63][RI/15/70])

Periodic systems: Floquet s transformation [RI/84/2] for optimal control [RI/91/06], robust control [RI/94/09]




General activites of the team SYNER AERES pdf1AERES pdf2AERES pdf3CNRS 2010


  • robust estimation and control of dynamical systems, i.e. differential equations and difference equations presenting various difficulties:

  • nonlinear phenomena (no superposition/separation property),

  • time-delay effects (differential-difference equations, with infinite dimension),

  • hybrid flow-and-jump behaviors (discrete/impulsive modes together with continuous states)

  • asynchronous sampling

  • finite-time convergence algorithms rooted in both the homogeneity concept (including sliding modes) and algebraic tools

  • interval observers


  • robotics & communication: networked/embedded/cyberphysical systems, Internet of things, handicap ;

  • fluid mechanics & micro/nano-technologies: boundary layer control ;

  • electrical engineering: power converters, sensorless control...

  • biology (‘living’ sensors)  

  • mathematics (homogeneity-based tools for control design, differential algebra)

See here for SYNER, there for CO2.