A Frequency Domain Toolbox Using Interval Arithmetic

In linear control theory the frequency domain approach and the state-space approach are equivalent. But for the implementation of numerical algorithms the use of state-space equations is preferred. To avoid the numerical problems caused by a polynomial arithemtic, the use of an interval arithmetic with variable length of the mantissa is suggested. Some basic algorithms for polynomial and transferfunction matrices implemented in interval arithmetic will be stated. A control example shows the feasibility of this method.