Self-repairing control via an unstable filter

This paper presents a new self-repairing control system (SRCS) for nonlinear plants with unknown sensor failures of a stuck-type. The SRCS can detect the failure and replace the faulty sensor with the healthy one. The advantage of the SRCS is that no plant model is required to detect the failure. Hence, one can construct the SRCS of an extremely simple structure. To achieve exact and early fault detection, an unstable filter and an auxiliary switching signal are introduced. The detection period can be shortened arbitrarily by choosing a large pole of the filter. Also, this paper shows an application to a nonlinear continuous stirred tank reactor. To confirm the effectiveness, several numerical experiments are explored. (C) 2009 Elsevier Ltd. All rights reserved.