An Undershooting Phenomenon and Its Control in Multi-Input-Output Servo Systems

Abstract

The undershooting phenomenon of a linear servo system is related to an increase of the rising time of the step response. In a single input-output system, it is well known that this phenomenon occurs when there are right half plane zeros of the transfer-function.
This paper discusses this undershooting phenomenon in multi-input and output systems from a linear structure point of view, and includes the following.
1) The necessary and sufficient condition to eliminate this undershoot is derived, and it is shown that this phenomenon is not directly related to invariant zeros in multivariable systems.
2) A design condition and a design procedure of a servo system having no undershoot are proposed and discussed.