Digital modelling and robust digital redesign of sampled-data uncertain systems via the interval tuning bilinear approximation method

Based on the bilinear approximation method, we present an interval tuning bilinear approximation method to do the digital model conversion and digital redesign of sampled-data uncertain systems. The tuning bilinear method together with interval arithmetic operation is employed to obtain the approximate discrete-time model and the digital robust control law from the continuous-time uncertain state equation and the given continuous-time robust control law, respectively. The proposed digitally tuning redesigned control law with one parameter can be adjusted so that the resulting dynamic states of the digitally controlled sampled-data uncertain system are able to closely match those of the original continuous-time well-designed uncertain system for a relatively longer sampling period.