  This paper deals with the parameter estimation problem of the
Single-Input-Single-Output (SISO) switched Hammerstein system. Suppose that the
switching law is arbitrary but can be observed online. All subsystems are
parameterized and the Recursive Least Squares (RLS) algorithm is applied to
estimate their parameters. To overcome the difficulty caused by coupling of
data from different subsystems, the concept "intrinsic switch" is introduced.
Two cases are considered: i) The input is taken to be a sequence of independent
identically distributed (i.i.d.) random variables when identification is the
only purpose; ii) A diminishingly excited signal is superimposed on the control
when the adaptive control law is given. The strong consistency of the estimates
in both cases is established and a simulation example is given to verify the
theoretical analysis.
