A wavelet-based robust M-estimation method for the identification of nonlin
ear systems is proposed. Because it is not based on the assumption that the
re is the class of error distribution, it takes a flexible, nonparametric a
pproach and has the advantage of directly estimating the error distribution
from the data, This M-estimator is optimal over any error distribution in
the sense of maximum likelihood estimation. A Monte-Carlo study on a nonlin
ear chemical engineering example was used to compare the results with vario
us previously utilized methods.