A discussion on sensor recovery techniques for fault tolerant multisensor schemes

Abstract

The present paper deals with the interplay between healthy and faulty sensor functioning in a multisensor scheme based on a switching control strategy. Fault tolerance guarantees have been recently obtained in this framework based upon the characterisation of invariant sets for state estimations in healthy and faulty functioning. A source of conservativeness of this approach is related to the issue of sensor recovery. A common working hypothesis has been to assume that once a sensor switches to faulty functioning it can no longer be used by the control mechanism even if at an ulterior moment it switches back to healthy functioning. In the current paper, we present necessary and sufficient conditions for the acknowledgement of sensor recovery and we propose and compare different techniques for the reintegration of sensors in the closed-loop decision-making mechanism.

Keywords:

• fault tolerant scheme
• invariant sets
• set membership testing

Notes

For the following numerical examples the manipulated sets will be considered to be polyhedral for their numerical reliability.

Note that, as mentioned in Seron, De Doná, and Olaru (2012) the switching has a leveling effect, in the sense that the closed-loop response is comparable with fusion strategies that use combined information from all sensors to compute the feedback law.

The same scheme can be generalised for any type of sensor faults with given fault signature matrix – Π:

This will imply exact full state measurement and represents an ideal case, which is given here to aid the reader in assessing the structural issues of the problems ahead.

The residuals belong to polyhedral sets as a consequence of the polyhedral characterisation of all the sets, which participate in their construction.

Additional information

Notes on contributors

Florin Stoican

Florin Stoican received the B.E. degree from the University Politehnica Bucharest, Romania, in 2008, and the Ph.D. degree from SUPELEC, France, in 2011. In 2012, he has held a postdoctoral position at NTNU Trondheim, Norway. His research interests include constrained optimisation, fault tolerant control (FTC) with set theoretic elements and mixed integer programming.

Sorin Olaru

Sorin Olaru received the M.S. degree from the University Politehnica Bucharest, Romania, and the Ph.D. degree from University Paris XI, France. Since 2001 he held different positions at INRIA and SUPELEC in France and visiting appointments at University of Newcastle, Australia and NTNU Trondheim, Norway. Currently, he is a Professor in SUPELEC and member of the INRIA Disco team. His research interests include optimisation-based control design and set theoretic characterisation of constrained dynamical systems.

José A. De Doná

José A. De Doná received the B.E. degree from Universidad Nacional del Comahue, Neuquén, Argentina, in 1989 and the Ph.D. degree from the University of Newcastle, Callaghan, Australia, in 2000. Since 2001, he has held various positions at the School of Electrical Engineering and Computer Science, the University of Newcastle, where he is currently an Associate Professor. His research interests include constrained control and estimation, model predictive control, nonlinear control and FTC systems.

María M. Seron

María Seron received the Electronic Engineer degree from the Universidad Nacional de Rosario, Argentina, in 1988 and the PhD degree from The University of Newcastle, Australia, in 1996. During 1997–1998, she held postdoctoral positions in Belgium, Australia and the USA. From 1999 to 2002, she was an Associate Professor with the Department of Electronic Engineering, Universidad Nacional de Rosario, Argentina. Since 2002, she has been a Research Fellow with the Centre for Complex Dynamic Systems and Control, The University of Newcastle, Australia. Her research interests include constrained control, FTC and hybrid systems.