First-order models for slow sampled-data multivariable systems: An asymptotic analysis

The combined modeling and control problem for -input/ -output synchronously sampled systems is considered as a parameterized control problem parameterized by the sampling interval . It is shown how successful designs can always be based on a rough and ready first-order model provided that the sampling rate is slow enough. One consequence of the results is a digital version of Davison\´s robust tuning regulator.