Zero assignment in the multivariable robust servomechanisms

Feedforward of the reference input is introduced to provide another degree of freedom in the overall system optimization of multivariable robust servomechanisms. This provides the designer with substantial control over the shape of the transient response. Introduction of the feedforward matrices has no effect on the pole locations or robustness properties of the system and creates new transmission zeros, the location of which can be influenced by proper selection of feedforward matrices. Loss functions such as the integral square error can be used to determine the feedforward matrices. Explicit formulas are derived for the feedforward matrices in terms of Lyapunov functions.