Active incipient fault detection with more than two simultaneous faults

The problem of detecting small parameter variations in linear uncertain systems due to incipient faults, with the possibility of injecting an input signal to enhance detection, is considered. Most studies assume that there is only one fault developing. Recently an active approach for two simultaneous faults has been introduced. In this paper we extend this approach to allow for more than two simultaneous faults. Having more than two simultaneous incipient faults is sometimes a natural assumption. A computational method for the construction of an input signal for achieving guaranteed detection with specified precision is presented for discrete time systems. The method is an extension of a multi-model approach used for the construction of auxiliary signals for failure detection, however, new technical issues must be addressed. A case study is examined.