A Radial Basis Function network (RBFN) is used to obtain a model of a gas e
ngine, an unstable two-input/single-output system (MISO-system), to be used
for the design of the speed control system. The RBFN-centers are chosen us
ing the stepwise orthogonalization algorithm, and an input space compressio
n which helps to avoid sparse data sets is presented. The influence of nois
y data is investigated in a nonlinear system example, in order to find the
cause of the model errors in the case of the gas engine model. The quality
of the nonlinear RBFN-model is demonstrated by comparing measured and simul
ated data.