We show how to perform targeting control using global models derived f
rom data coming from possibly nonstationary dynamical systems where th
e varying parameters are known along with the System observations. We
first identify a global model from the observations and the values of
the accessible parameters. To carry out the control, we successively a
pply the usual targeting algorithm to the model system to get a pertur
bation of the accessible parameters for a given starting point and tar
geting point, then apply this perturbation to the true system to gener
ate a new starting point. Because our model is approximate, we repeat
the targeting and perturbation steps until the observed trajectory is
near the target point. (C) 1997 Elsevier Science B.V.