Robust and optimal control at small scales

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Due to their small sizes, microsystems and micromechatronic systems are very sensitive to environmental disturbances (temperature, vibrations, etc.) and to the interaction and contact with surrounding systems (manipulated objects, other microsystems) making their behavior time and tasks dependent. Additionally to these, most of them typify strong nonlinearities (high degree polynomial, hysteresis, creep/drift, …) as they are based on smart and active materials and exhibit badly damped oscillations as they include cantilever structures. All these phenomena need that the systems have to be controlled in order to reach the severe performances required in the applications (precise and high dynamics positioning). However additional challenges during the control synthesis are the low signal-to-noise ratio that are specific to micro-world and the lack of convenient sensors. The works of the CODE-team here consist in adapting the 'traditional' control techniques in order to include these properties (strong nonlinearities, badly damped oscillations, high environmental sensitivity, noisy signals, lack of sensors, time- and task- dependent models, …) when controlling micromechatronic systems and to satisfy the performances required in the applications. The adaptation may starts from the modeling, or during the controller synthesis. Different 'traditional' control techniques are studied for that: robust (H-inf, µsynthesis, RST,...), optimal (LQ, LQG,...), adaptive, multimodel and multimodal...

Fig.1 Control of micromechatronic systems.

Selected publications

Juan Antonio Escareno, Joël Abadie, Emmanuel Piat and Micky Rakotondrabe, ' Robust Micro-positionnig Control of a 2DOF Piezocantilever Based on an Extended-State LKF', IFAC - Mechatronics (MECH), accepted.

Jie Ling, Micky Rakotondrabe, Zhao Feng, Min Ming, and Xiaohui Xiao 'A Robust Resonant Controller for High-speed Scanning of Nanopositioners: Design and Implementation', IEEE - Transactions on Control Systems Technology (T-CST), accepted with minor revisions.

Omar Aljanaideh and Micky Rakotondrabe, 'Observer and robust H-inf control of a 2-DOF piezoelectric actuator equiped with self-measurement', IEEE - Robotics and Automation Letters (RA-L), Vol.3, Issue.2, pp.1080-1087, April 2018.

Didace Habineza, Micky Rakotondrabe and Yann Le Gorrec, 'Characterization, Modeling and H-inf Control of n-DOF Piezoelectric Actuators: Application to a 3-DOF Precise Positioner', Asian Journal of Control (AJC), DOI=10.1002/asjc.1224, Vol. 18, No. 5, pp. 1–20, September 2016.

Juan Antonio Escareno, Micky Rakotondrabe and Didace Habineza, 'Backstepping-based robust-adaptive control of a nonlinear 2-DOF piezoactuator', IFAC - Control Engineering Practice (CEP), Vol.41, Pages 57-71, August 2015.

Contact:

Micky Rakotondrabe