This paper presents a disturbance decoupled fault reconstruction (DDFR) scheme using cascaded sliding mode observers (SMOs). The processed signals from a SMO are found to be the output of a fictitious system which treats the faults and disturbances as inputs; the ‘outputs’ are then fed into the next SMO. This process is repeated until the attainment of a fictitious system which satisfies the conditions that guarantee DDFR. It is found that this scheme is less restrictive and enables DDFR for a wider class of systems compared to previous work when only one or two SMOs were used. This paper also presents a systematic routine to check for the feasibility of the scheme and to calculate the required number of SMOs from the outset and also to design the DDFR scheme. A design example verifies its effectiveness.
- Disturbance rejection
- Sliding mode
- Fault diagnosis
Ng, K., Tan, C. P., & Oetomo, D. (Accepted/In press). Disturbance decoupled fault reconstruction using cascaded sliding mode observers. Automatica, 48(5), 794-799. https://doi.org/10.1016/j.automatica.2012.02.005