The Kohonen self-organizing map (KN) was developed for pattern recognition,
and has been extended to fault classification. However, the KN cannot be a
pplied to classify faults from the system output if it contains other facto
rs, such as system state and sensor mounting errors. To overcome this probl
em, a constrained KN (CKN) is proposed. To eliminate the effect of the syst
em state and the mounting errors, it is proposed that the weight vectors of
the CKN are constrained in the parity space. The training algorithm of the
CKN is derived, and its convergence discussed. Application of the CKN to f
ault classification is presented, and its performance is illustrated by an
example involving a redundant sensor system with six sensors. (C) 2001 Else
vier Science Ltd. All rights reserved.